Burg Waldenstein, Medieval castle in Rudersberg, Germany.

Burg Waldenstein is the ruin of a spur castle on a 385 m high mountain spur above the Wieslauftal valley in the Waldenstein district of Rudersberg. Its core is the Altes Schloss, a two-storey stone house with Staufen buckled ashlar masonry and a shield wall; the wall facing attackers is 3.5 m thick, the courtyard wall 1.5 m. The neck ditch is filled in and the ring wall is incomplete.

The castle was built around 1200 by the Lords of Waldenstein, probably Staufen ministerials, and first documented in 1251 when they served Württemberg. In 1456 Count Ulrich granted it as a fief to Antony von Emershofen, and in 1535 it was described as dilapidated. In 1792 the ducal chamber sold the ruin to the Rudersberg office, and a fire destroyed the Renaissance building and a round tower in 1819.

The name Waldenstein comes from the Lords of Waldenstein, who built the castle around 1200 and were first documented in 1251. A restaurant has occupied the former castle grounds since 1963, so visitors today eat and drink on the site of the medieval complex.

The ruin sits on a 385 m spur above the Wieslauftal; the filled-in neck ditch and incomplete ring wall are freely accessible. A restaurant has occupied the former castle grounds since 1963. The nearest rail station is in Schorndorf, about 15 km away, from where bus or taxi continue to Waldenstein.

The castle had no bergfried, only a neck ditch and a ring wall; the ditch is filled in today and the wall survives only in parts. The two-storey stone house, called the Old Castle, keeps Staufen humped ashlar masonry, with a 3.5-metre wall facing attackers and a courtyard wall of just 1.5 metres.