[1] Today it houses the Kantonale Jugendheim, for holding and rehabilitating juvenile offenders.

The Vogtei (a bailiff or vogt was an overlord exerting guardianship or military protection as well as secular justice (Blutgericht) over a certain territory, the Vogtei) was created to better control and monitor the important north–south trade route over the Aare River.

Only later, once Bern had suppressed the rights of the nobility and the clergy, additional bailiwicks were added: Lenzburg (1442),[3] Schenkenberg (1460), Biberstein (1499) Zofingen (1528), Königsfelden (1528) and Kasteln (1732).

[4] Its purpose was to protect the connection between the Protestant towns of Bern and Zurich at the narrowest point of the Bernese dominion and thus complicate any attacks from Catholic neighbors.

The Cantonal Parliament decided in 1891 to establish an "institution for juvenile criminals and scoundrels" in the castle.

The keep's walls are 3 to 3.5 metres (9.8 to 11.5 ft) thick, and consist entirely of limestone.

In 1621/22 the castle grew toward the south, with an additional living area and stair tower.

The cell block on the south side was replaced in 1954/55 by a house for the educational staff, but it was built in harmony with the historic buildings.