Burgruine Bottenstein, Castle ruin in Wikon, Zofingen, Switzerland

Burgruine Bottenstein is the ruin of a spur castle on a wooded molasse rock at the eastern edge of Zofingen, on the border with Lucerne. Its square keep measured 12.5 metres per side, with a residential building (8.5 × 12.5 metres) attached to the west; the walls of the latter survive up to nearly one metre high. A single rounded stone pillar stands in the open interior, and the walls are built of stacked flat grey and brown stones.

The castle was probably founded in the mid-13th century by a local ministerial family that moved its seat from Bottenwil; knight Ulrich von Bottenstein is first documented on 28 June 1255. After the family died out, the castle passed as a fief to the Aarburgs and later to the Rüsseggs. It was likely abandoned shortly after 1400 and already in ruins by 1460. Zofingen acquired it in 1483, and its remains were removed in the 1830s; Reinhold Bosch excavated the foundations in 1949/1950.

The name Bottenstein derives from Bottenwil, the village the founding family left for this hill; variants Botanstein, Bottinstein and Bottensteyn are recorded. Bottenwil still bears part of the lords' coat of arms in its municipal arms. The site is freely accessible and protected as a class B cultural property of regional significance since 5 May 1950.

The ruins lie about 800 metres south-west of Bottenwil's village centre, on the easternmost tip of Zofingen's territory, and are freely accessible at any time. The cantonal border between Aargau and Lucerne runs straight through the castle area, so you cross from one canton into the other on foot. The walls of the residential building stand barely one metre high.

The finds from the 1949/1950 excavations under cantonal archaeologist Reinhold Bosch — pottery shards, crossbow bolts and Gothic stove tiles with a lion motif — all date to the 13th and 14th centuries. The site was protected as a cultural property on 5 May 1950.