The Einstein Tower is the most impressive construction on the Telegrafenberg Hill in Potsdam. It is the first and one of the most famous constructions by the architect Erich Mendelssohn. The tower was completed in 1924 and is esteemed to be one of the most inventive and most important buildings of the 20th century. Until World War II Einstein Tower used to be the scientifically most important solar telescope in Europe. Today the Leibniz Institute for Astrophysics operates the solar observatory in the tower. The outside tour of the Einstein Tower is possible at any time during the day and is highly recommended. Please register at the entrance to the Science Park.