Medieval castle ruins Fürstenstein, Archaeological site and castle ruins in Ettingen, Switzerland.

Fürstenstein is castle ruins in Ettingen, located on elevated ground and made of medieval stone remains. The preserved walls and structures offer insight into the defensive architecture of fortifications from that period.

Fürstenstein is first documented in 1302 as a Basel bishop's fief held by the lords of Rotberg, who likely founded it. Habsburg troops besieged it during King Albrecht's war with the Bishop of Basel, withdrawing after Albrecht was murdered on 1 May 1308. Damaged in the Basel earthquake and repaired, it was destroyed by Basel in 1411-1412 after Heinrich zu Rhein and Rudolf von Neuenstein attacked it during Katharina of Burgundy's feud. In 1515 the ruin and Rotberg rights were sold to Solothurn.

The name Fürstenstein first appears in 1302 as a Basel bishop's fief held by the lords of Rotberg, who likely built it. In 1410 the former Basel mayor Hans Ludmann von Rotberg withdrew to the fortress; after his ally Katharina of Burgundy feuded with Heinrich zu Rhein and Rudolf von Neuenstein, the two attacked the castle, and Basel destroyed it and beheaded the garrison.

Access is from the southeastern end of the narrow rock ridge, reached from Ettingen or Hofstetten-Flüh at the entrance to the Wallental; the final stretch involves some scrambling and sturdy footwear. The rock-cut staircase and the 1864 platform wall stand at the eastern, wider end of the ridge.

The visible wall at the eastern end is a platform built in 1864, not medieval masonry. South of the ridge the ground was artificially terraced, probably for farm buildings, and faint holes in the southern rock face may be beam sockets.