When it opened on the cusp of the new millennium, London’s Tate Modern expected two million visitors a year. But within a year – that had become five million: the world’s most popular museum of modern and contemporary art.
To make room for everyone, it’s built a vast new extension – the Switch House designed by architects Herzog and De Meuron and named after the power station which occupied the building before. As well as displaying more art, it will also give house room to more diverse, international artists.