Burg Altendorf, Medieval castle ruins in Essen, Germany

Burg Altendorf is a ruined lowland castle on a peninsula south of the Ruhr, divided into an outer bailey and a main castle. The outer bailey has a trapezoidal plan with remains of round corner towers, while the main castle is enclosed by a rectangular ring wall 29 by 30 metres and five metres high. In its centre stands a five-storey residential tower, now 21.70 metres high, built of local Ruhr sandstone.

Burg Altendorf was built in the second half of the 12th century in Romanesque style. The Lords of Altendorf are documented from 1297 as liegemen of the Counts of the Mark, holding the hereditary office of steward of Essen Abbey. In 1386 the castle passed solely to the von Vietinghoff-Schell family, who had it extensively rebuilt from 1533.

The castle gave the Essen district of Burgaltendorf its name. The residential tower, called a Donjon, is the largest surviving one between the Rhine and the Weser. Its cellar with a barrel vault served in the 17th century as the prison of the Blankenstein office, and the bases of the columns that carried its former cross vault remain at the four corners.

The outer area of the castle is owned by the city of Essen and can be visited freely at any time. A steel bridge with wooden planks links the outer bailey to the inner castle, and a modern spiral staircase inside the residential tower leads up to a viewing platform.

The castle keep, 21.70 metres high, is the largest surviving residential tower between the Rhine and the Weser. Its former cellar, now the ground floor, served in the 17th century as the prison of the Blankenstein district office. Bases of columns that carried its cross vault remain at the four corners.