The remains of the Castle can be visited
CastleGoslar - Vienenburg
Vienenburg Castle

The Vienenburg castle ruin, a former hilltop castle, sits on a ridge near Vienenburg in the district of Goslar, Lower Saxony.
History+
After Bishop Siegfried II besieged and razed Harliburg in 1291, the Count of Wernigerode used the salvaged stones to construct Vienenburg in 1306. In 1367, the counts sold the castle to Bishop Gerhard. In 1523, it became part of the Principality of Brunswick-Wolfenbüttel. During the Thirty Years' War, Wallenstein conquered Wiedelah from here in 1626. From 1643 to 1802, Vienenburg belonged to the Prince-Bishopric of Hildesheim.
Image: http://de.wikipedia.org/wiki/Datei:Burgruine_Vienenburg_Ringmauer.jpg
Location: 51.9476, 10.5638