The Strandbad Wannsee is an open-air lido on the eastern shore of Großer Wannsee lake, a large bay of the Havel river in Berlin, Germany. Opened in 1907, it is one of the largest inland lidos in Europe, with a beach that is 1,275 metres (4,183 ft) long and 80 metres (260 ft) wide,[1] replenished with sand from the Baltic coast.[2] The entire ensemble of long, low buildings that appear to grow out of the underlying sandhills were designed by Richard Ermisch and fellow architect Martin Wagner in 1929–1930;[3] it is today placed under monumental protection.