Photograph by Chris Ratcliffe/Bloomberg
The views are outstanding. You look down (just) on the 180-meter Gherkin and you can see across to the Olympic Park and beyond. Sushisamba is worth visiting for this terrace alone, The screen that separates you from overfamiliarity with the street below is disconcertingly low. If you're scared of heights, Sushisamba may be Hitchcockian in the terror it induces.