This district of ultra-modern tower blocks was one of the busiest junctions in Europe in the 19C. Badly damaged during the Second World War, it was cut in two by the Wall, leaving a huge wasteland to the east. Since reunification, Potsdamer Platz and its district have been rebuilt, creating one of the most important centres of contemporary architecture in Europe. Note the traffic light tower in the middle of the square, a replica of the systems once used in Europe, originally installed here in 1925.