First look: inside the Switch House – Tate Modern's power pyramid

With its chainmail brickwork, vast spaces and panoramic views, the Tate’s £260m ziggurat is a mesmerising twist on the existing art galleryAmong the shafts of luxury flats sprouting up along the south bank of the Thames, from Battersea to Bermondsey, there is one new tower unlike the others. It is made of brick, not glass, and stands as a squat, truncated pyramid, twisting as it rises. Punctured only by thin slit windows, Tate Modern’s new extension rears up like a defensive wa