Voussoirs

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The Rocky Mountain Laboratories possess national significance due to the pioneering research conducted at these laboratories from 1921-1945 toward the development of vaccines for insect-borne dise More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: The federal section of the Baltimore-Washington Parkway was constructed to provide a dignified entrance to the nation's capital. The parkway also provided a new traffic artery that relieved conge More

Significance: Built of native sandstone and ashlar masonry, and designed to complement its natural surroundings, this bridge is a superb example of "National Park Service-Rustic" stone bridge engineering. It i More

Significance: Built of native sandstone and ashlar masonry, and designed to complement its natural surroundings, this bridge is a superb example of "National Park Service-Rustic" stone bridge engineering. It i More

Significance: Built by the State Highway Commission in 1927, the Eau Claire Dells Bridge is an early example of a stone faced, reinforced concrete span. The single arch, filled spandrel design uses locally gat More

Significance: Built by the State Highway Commission in 1927, the Eau Claire Dells Bridge is an early example of a stone faced, reinforced concrete span. The single arch, filled spandrel design uses locally gat More

Significance: Built by the State Highway Commission in 1927, the Eau Claire Dells Bridge is an early example of a stone faced, reinforced concrete span. The single arch, filled spandrel design uses locally gat More

Significance: Built by the State Highway Commission in 1927, the Eau Claire Dells Bridge is an early example of a stone faced, reinforced concrete span. The single arch, filled spandrel design uses locally gat More

Public domain image of a train station in Boston, Massachusetts, free to use, no copyright restrictions - Picryl description

Picryl description: Public domain vintage artistic photograph, free to use, no copyright restrictions image.

Picryl description: Public domain vintage artistic photograph, free to use, no copyright restrictions image.

Public domain image of a train station in Boston, Massachusetts, free to use, no copyright restrictions - Picryl description

Picryl description: Public domain vintage artistic photograph, free to use, no copyright restrictions image.

Picryl description: Public domain vintage artistic photograph, free to use, no copyright restrictions image.

Picryl description: Public domain vintage artistic photograph, free to use, no copyright restrictions image.

Picryl description: Public domain image of a bridge, water, historic structure, free to use, no copyright restrictions.

Public domain photograph of apartment building, architectural plan, architecture, free to use, no copyright restrictions image - Picryl description

Public domain scan of an architecture diagram, architectural drawing, building plan, or design, free to use, no copyright restrictions - Picryl description.

Public domain photograph of apartment building, architectural plan, architecture, free to use, no copyright restrictions image - Picryl description