The remains of the Castle can be visited
Alt-Lägern Castle (Ruin) (Boppelsen)

The Alt-Lägern ruin, also known as Hohen- or Altlägern, is on a narrow ridge of the Lägern near Boppelsen.
History+
The construction of Alt-Lägern Castle is dated between 1244 and 1246. It served as the seat of the Knights of Lägern, vassals of Baron Lütold V, who founded the town of Regensberg during this period. The castle was destroyed before the year 1300, possibly during the Regensberg Feud around 1267, which led to the decline and extinction of the Lords of Lägern. Excavations took place between 1902 and 1904 but remained unfinished. In 1982, the severely damaged walls were restored by the municipality of Boppelsen and the Canton of Zurich.
Source: Wikipedia · Licence: CC BY-SA 4.0
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: 47.4819, 8.3940