The Three Sisters bridges—Sixth Street, Seventh Street, and Ninth Street—were built between 1925 and 1928 after the War Department determined that the existing bridges over the Allegheny were too low and impeded navigation. As engineering feats they are technically interesting: they had to be made self-anchoring to avoid tearing out huge chunks of valuable property downtown. As architecture they are memorable, and not just because this is the only place in the world where you can see three identical suspension bridges side by side. The Sixth Street Bridge, now named for Pirates star and philanthropist Roberto Clemente, was the most beautiful steel bridge built in America in 1928.

On baseball days the bridge is closed to motor vehicles, which allows a gentleman in a powdered wig to stand right in the middle of it with his Kodak.

The architect was Stanley Roush, the king of public works in Pittsburgh at the time. You may think Father Pitt was being a bit hyperbolic in calling this the most beautiful steel bridge of 1928, but he was merely reading off its credentials.