The former Bankside Power Station, built in 1945 by Sir Giles Gilbert Scott, has been converted to house the Tate Gallery’s collection of modern art. This imposing structure was originally laid out in three parallel tracts: on the side facing the Thames was the boiler house; in the middle was the space for the turbines; and on the south side was the switch house. The architects Herzog & de Meuron have retained this tripartite division. A broad ramp leads down from the western end into the huge entrance space – still known as the “Turbine Hall” – which extends over the entire length and height of the building like a broad concourse. To the left is the new facade of the gallery tract with its striking, illuminated bay windows that seem to float above the vast hall. The internal facade on the opposite side is closed at present, but behind it are spaces that will later be added to the gallery. A further relic of past times is the bridge that spans the main area and links up with the northern entrance. The bridge is all that remains of a floor slab, which, prior to the conversion, extended over the whole length of the power station. The removal of this floor allowed the Turbine Hall to be opened up to its present ample dimensions. The bridge, from which visitors have a view over the hall, leads into the gallery tract, where escalators ascend to the upper levels.