The Oberbaumbrücke (Oberbaum Bridge) in Berlin was built from 1894 until 1896 and connects the districts Friedrichshain and Kreuzberg spanning across the River Spree. It is a double decker bridge; on the bottom you have cars, bikes, and pedestrians cross while the subway U1 runs on the top.
It used to serve as a toll bridge, during the Cold War it was a border crossing between East and West Berlin, and after its renovation in the 1990s it is now called Berlin’s most beautiful bridge.
Read more about the rich history of the Oberbaum Bridge here: