to be cut over 10 metres deep into the layer of chalk marl. During high water the Calenberg still rises like an island in the surrounding floodwaters. The name Calenberg clearly indicates that the chalk marl stratum was not tree-covered, but stood proud of the Leine meadows as a "bare hill". The river terrace of the Leine had, in former times, laid down gravel to the north and south of the chalk marl step, that was later covered with loess and river loam (Auelehm). The builders of the water castle used this gravel, loess and loam to build the ramparts. Stone for the foundation walls and fortifications of Calenberg Castle were extracted from a quarry on the north side of the Calenberg, which was used until the second half of the twentieth century as a rubbish tip and then covered with topsoil. Water castle The old water castle was built on the island of Calenberg as a lowland fort in the middle of the River Leine, which used to form the border of the episcopal region of Hildesheim. The castle was laid out on a raised plateau about 50 × 70 m in area. Around it was a moat, which was later refilled when the castle was rebuilt into a much larger fortification. Originally the water castle was a three-storey motte and bailey structure (Turmhügelburg) with a floor plan of 14.4 × 14.4 m. It had a residential wing to the north. The castle dominated the military road or Heerstraße from Gestorf through the Leine valley to Hildesheim. Although the castle had an important location as a border fortification, it was enfeoffed as early as 1327 to the knight, Conrad of Saldern, due to a lack of funding. He was also permitted to establish an unfortified town to the south of the castle. The settlement of Lauenstadt, founded in 1327, never fully developed however. In 1613 it ranked last in a list of towns in the Principality of Calenberg. Until about 1900 markets were held in Lauenstadt, at which everyday items were sold in open stalls. By 1350 the castle had been enhanced with a long west wing (32.6 × 9.6 m) adjoined by another gate tower (13.9 × 13.9 m). The rest of the bailey was surrounded by a curtain wall. In 1363 there was a mill belonging to the castle and a customs station on the Leine bridge.