 The "Christoffelturm" remained the western border of Bern until the nineteenth century.From 1622 to 1634 a series of defensive walls and strong points were added outside the "Christoffelturm".These defensive walls, known as the "Grosse Schanze" and "Kleine Schanze" (large and small redoubts respectively) as well as the "Schanzegraben" (redoubt ditch or moat), were never used as living space for the city, though the "Schanzengraben" was used for a while to house the Bärengraben.