The Lingotto Building was once a huge car factory constructed by Fiat. Built by Giacomo Mattè Trucco and finished in 1923, its design was unusual in that it had five floors, with raw materials going in at ground level. Cars were built on a ramp that went up through the building. Finished cars emerged at rooftop level, where there was a test track. It was the largest car factory in the world at the time. The Lingotto Building was avant-garde, influential and impressive. Le Corbusier called it "a guideline for town planning". The factory became outdated in the 1970s and finally closed in 1982. After closure there was a lot of debate about its future. An architectural competition was held, which was awarded to Renzo Piano who envisioned an exciting public space for the city. The old factory was rebuilt into a modern complex with concert halls, a theatre, a convention centre, shopping arcades and a prestigious hotel.