Burgruine, Castle ruins in Arnstein, Germany

Schloss Büchold is a castle ruin in Büchold, a district of Arnstein in Lower Franconia. Its circular layout is dominated by a 26-metre-high round Romanesque bergfried, or keep, at the centre. The ring walls were stabilised and partly rebuilt during restoration work between 2009 and 2011.

Büchold Castle was first documented in 1299 as a "castrum" and branch of the Würzburg Johanniter house. After the Johanniter fell into debt it passed to the Counts of Rieneck, and in 1364 to the Lords of Thüngen, who held it over 200 years and rebuilt the Romanesque castle into a Renaissance palace. From 1596 Dietrich Echter von Mespelbrunn imposed a strict re-Catholicisation; accused women were tortured in the castle dungeon and burned at the Galgenberg. From 1652 to 1749 it was a fief of the families von Dalberg, von Greiffenclau and von Ingelheim, who laid out a Baroque garden east of the castle. After 1769 it decayed, the Renaissance buildings were demolished from 1776, and in 2007 Susan Schubert and Henning Glawatz bought the ruin, restored 2009–2011.

Büchold's Lutheran faith arrived with the von Thüngen family around 1540, and the parish church of St. Nikolaus und Mariä Heimsuchung still shows the shape given it under Philipp Christoph Echter during the Counter-Reformation. The baroque garden laid out east of the castle by the Dalbergs survived over 100 years; its entrance was restored in 2006 by the Vereinsring Büchold.

The ruin lies in Büchold, a district of Arnstein, not in Arnstein's town centre. The site is a private property with a house built inside the former castle grounds in the 2000s, so visits are best limited to the exterior and the restored baroque garden entrance east of the castle, repaired in 2006.

The round Romanesque bergfried, 26 metres high, stands at the centre of the circular complex; it was conserved and the ring walls stabilised and partly rebuilt during the 2009 to 2011 renovation. The baroque garden laid out east of the castle by the Dalbergs lasted over 100 years, and its entrance was restored in 2006 by the Vereinsring Büchold.