The Cour Carrée (Square Courtyard) of the Louvre replaces part of the medieval castle, built by Philippe Auguste in the 12th century. At the time, the castle was fortified by a dozen towers and ditches, and had a central keep 31 metres high. In 1545, in order to rebuild the castle in the Renaissance style, François I had the keep and two wings razed. The larger present courtyard lined with pavilions was completed under Louis XIV. In the western square of the courtyard, two grids cover an old well and cistern, in use until 1528. In the same place, the line of the former keep is marked by the paving stones, laid in a different direction.