The remains of the Castle can be visited
Böbikon Castle

The medieval hilltop castle ruin of Böbikon is situated in the municipality of Böbikon in the canton of Aargau. Its history is sparsely documented.
History+
Archaeological findings suggest that the castle originated around the year 1100. An Erfridus von Bebikon, mentioned in a document in 1113, could be considered the possible builder of the first complex. This initially consisted of a curtain wall enclosing a building. At the beginning of the 13th century, a new construction phase took place, giving the castle a pentagonal curtain wall with a gate located on the west side.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Ruine_B%C3%B6bikon_2012-12-16_17.31.13.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 47.5548, 8.3278