The Senate Square and its surroundings form a unique and cohesive example of Neoclassical architecture. The square is dominated by four buildings designed by Carl Ludvig Engel between 1822 and 1852: Helsinki Cathedral, the Government Palace, the main building of the University of Helsinki and the National Library of Finland. A statue of Alexander II (1894) stands in the middle of the Senate Square. Helsinki Cathedral is arguably Finland’s most famous and photographed building; it celebrates its 165th anniversary in 2017. The oldest stone building in Helsinki is the Sederholm House located on the southeast corner of the square. Today the building hosts the Helsinki City Museum. The church is part of Helsinki’s Empire era centre and a landmark for those arriving by sea. It has become the symbol of the whole of Helsinki. Earlier called St. Nicholas Church and Great Cathedral, the current main church of the Helsinki Diocese was completed in 1852. Sculptures of the twelve apostles guard the city from the roof of the church.