 During the second expansion, to the Käfigturm, the Zytglogge wall was removed and the tower was relegated to second-line status.Around 1270–1275 an additional 7 m (23 ft) was added to the tower to allow it to overlook the surrounding houses.After the third expansion, to the Christoffelturm, the Zytglogge was converted into a women's prison.