Escher in the Palace one's eyes will be tricked by multiple interactive displays. In the rooms of the museum are fifteen chandeliers made by the Rotterdam artist, Hans van Bentem. The artist designed these especially for the museum, with some references to the work of Escher and the Palace. In the ballroom, a star chandelier is endlessly reflected in the two mirrors. In other rooms there are chandeliers such as a shark, a skull, spiders, and a sea horse. The parquet floor in the Palace was designed in 1991/92 by the American minimal artist Donald Judd on the occasion of the opening of the
Palace of Westminster paved over and covered in concrete security blocks ("see security below"). Cromwell Green (also on the frontage, and in 2006 enclosed by hoardings for the construction of a new visitor centre), New Palace Yard (on the north side) and Speaker's Green (directly north of the Palace) are all private and closed to the public. College Green, opposite the House of Lords, is a small triangular green commonly used for television interviews with politicians. The Palace of Westminster contains over 1,100 rooms, 100 staircases and of passageways, which are spread over four floors. The ground floor is occupied by offices, dining