The Oberbaum Bridge (Oberbaumbrücke Bridge), Berlin, Germany (photo)

The Oberbaum Bridge (German: Oberbaumbrücke) is a double-deck bridge crossing Berlin's River Spree, considered one of the city landmarks. It links Friedrichshain and Kreuzberg, former boroughs that were divided by the Berlin Wall, and has become an important symbol of Berlin’s unity. The lower deck of the bridge carries a roadway, which connects Oberbaum Straße to the south of the river with Warschauer Straße to the north. The upper deck of the bridge carries Berlin U-Bahn line U1, between Schlesisches Tor and Warschauer Straße stations. The bridge is built on the former boundary of the municipal area with its rural environs, where an excise wall was built in 1732. A wooden drawbridge was built as part of the wall; it served as a gate to the city. The name Oberbaumbrücke stemmed from the heavy tree trunk, covered in metal spikes, that was used as a boom to block the river at night to prevent smuggling. (Baum means tree or wooden beam in German; thus the name means something like "Upper [Upstream] Tree Bridge"; there was another tree-trunk barrier at the western end of the contemporary city limits, close to today's Unterbaumstraße (lit. in English: Lower [Downstream] Tree Street.) Photographed in 2013