The Bridgewater Hall, completed and opened in 1996, is a very contemporary building in design and in its use of mixed materials. The base of the building is deep red sandstone from Corsehill quarry, Annan, with upper walls of aluminium cladding and glass and steel, with an interior of Jura Limestone. Costing £42 million to build and hosting over 250 concerts each year, the Hall is the home of the Hallé Orchestra and regular venue for concerts by the BBC Philharmonic orchestra. Outside the building on the plaza is the highly sensual ‘Touchstone’, a sculpture by Kan Yasuda made of Italian Carrara marble which is white but streaked with flashes of bluish/grey. Marble is a metamorphosed limestone, altered from its original form when subjected to the high heat and pressure conditions associated with tectonic movements of the Earth’s crust.