Reading, PA, United States
Skew Bridge. Regarded best example of Skew Bridge in U.S. Designed by Richard Osborn for the P & R Railroad in 1857. Each course of the arch of 40 feet is laid in ellipsoidal curve, each stone properly curved. There is no keystone.
Listen to the audio guide for Blue plaque № 28490 Free on WIP — starts by itself when you arrive, even with the screen off