Erguel Castle

Sonvilier, Switzerland, Switzerland

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Erguel Castle is a ruined medieval fortress southeast of Sonvilier in the Canton of Bern, Switzerland, likely built in the 11th century by the Lords of Erguel who settled there from Franche-Comté.

First documented before 1264, it became the Prince-Bishop of Basel's southernmost stronghold after Otto von Erguel ceded it in 1264, featuring expansions like a round bergfried tower, gatehouse, chapel, and living quarters under Bishop Heinrich of Isny.

Burned by Bernese forces in 1368 and later used as a prison and garrison, it fell into ruin by 1754 when the diocese abandoned it, with modern restorations in the 20th century preserving it as the best-preserved castle ruin in the French-speaking Bernese Jura.