The Fernsehturm (TV tower) at Alexanderplatz in Mitte is among the tallest structures in the European Union at . Built in 1969, it is visible throughout most of the central districts of Berlin. The city can be viewed from its  observation floor. Starting here, the Karl-Marx-Allee heads east, an avenue lined by monumental residential buildings, designed in the Socialist Classicism style. Adjacent to this area is the Rotes Rathaus (City Hall), with its distinctive red-brick architecture. In front of it is the Neptunbrunnen, a fountain featuring a mythological group of Tritons, personifications of the four main Prussian rivers, and Neptune on top of it.