Number 10 Ludgate Place may not be as famous a London landmark as Number 10 Downing Street, but the city's planning officials still expressed their desire for the new building to reflect London's architectural traditions. The building's elaborate cladding system includes stone used in a unique and innovative way. Like virtually all contemporary stone cladding, the granite used on 10 Ludgate Place consists of thin slabs hung on the building frame. In this case, however, instead of following the wall planes as a veneer, the stone slabs project from the aluminum and glass curtain wall to form a series of vertical fins or ribs. The stone used on 10 Ludgate -- dark green New Ubatuba granite -- was quarried in Brazil. The slabs -- 50mm thick, 2 meters high, and of varying depths -- were each supported by four 40mm stainless steel pins that pass through the stone and transfer its weight to aluminum mullions anchored to the building frame.