Mount Gediminas or Castle Hill is an erosional hill in Vilnius at the confluence of the Neris and Vilnia Rivers. Altitude – 142 metres, relative height – 48 metres.
It is an anthropogenically-modified slope of erosive origin, transformed into a fortified castle site in the Middle Ages.
The slopes of Mount Gediminas are steep (35–40°), with an oval site that is 110–120 metres long and 50–60 metres wide. The Vilnius Upper Castle (Gediminas Castle) stands on the hill. Castle Hill belongs to the Vilnius Castles Cultural Reserve.
Mount Gediminas has partly collapsed over the centuries. Its collapse was one of the factors in requiring fortification, and its landslides served as one of its defensive functions.
Trees started growing on the hill in the early 20th century and by the end of the century Mount Gediminas was completely covered with trees. They were completely cut down in 2011–2013.
In February 2016, landslides and subsidence began to occur on the slopes of Gediminas Tower as the soil thawed and soaked. Later, in 2016-2017, landslides were even more severe and work on Mount Gediminas was initiated. The formation of landslides could have been influenced by the funicular on the slope of the hill and the rebuilding of the Palace of the Grand Dukes of Lithuania at the foot of the hill.
The Castle Museum was opened in 1960 and has been operating as a division of the National Museum of Lithuania since 1968. The Gediminas Tower exhibition introduces the reconstruction models, armament and iconographic material of old Vilnius from the second half of the 14th century to the beginning of the 17th century. At the top of the tower is a viewing platform, which offers a magnificent panorama of Vilnius.