Significance: The stone arch bridge at Rockville's remains the world's longest of its type. It best represents the Pennsylvania's Railroad's monumental capitol investment and desire for "permanent" structures a More
Significance: The stone arch bridge at Rockville's remains the world's longest of its type. It best represents the Pennsylvania's Railroad's monumental capitol investment and desire for "permanent" structures a More
Significance: The stone arch bridge at Rockville's remains the world's longest of its type. It best represents the Pennsylvania's Railroad's monumental capitol investment and desire for "permanent" structures a More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More
Significance: The bridge is unusual two-level structure built to carry two different Pennsylvania Railroad branches. The low-grade freight line on the upper level was chief engineer William H. Brown's last majo More