Tate Modern art gallery, London, England. This is the massive entrance hallway, sometimes used as an exhibition space for the largest exhibits. The art gallery (also a museum of modern art) was created by converting an existing building, the Bankside Power Station. This hallway once housed the power turbines that generated electricity, so it is also called the turbine hall. It is 140 metres long and 35 metres high. Other exhibits are housed on the surrounding floors. The conversion was carried out by architects Herzog and de Meuron. The gallery opened on 12 May 2000. The original power station was built in two stages from 1947-1963. It closed in 1981.