Known as the Bärengraben, it was built in 1857, and is still in use though much modified:  after an outcry around 2000, when the bears were still in two circular pits and shut up at night, a park was constructed on the riverbank by the pits with generous access to the river Aare which has greatly improved the three bears' accommodation.
The Bärengraben, built in 1857, remains in use although it has undergone considerable transformations: following a public protest around 2000, when the bears were confined to two circular enclosures at night, a park was created on the riverbank adjacent to the pits, greatly improving the three bears' living conditions.