All hail London's rooftop season. On May 1, The Berkeley opened its rooftop to non-guests for the summer. The return of its “Capri in the city” pop-up – this year in collaboration with Acqua di Parma – brings lemon trees, striped loungers and Amalfi-hued spritzes to one of London's most coveted pools, with wide-angle views stretching across Hyde Park and the red-brick crescents of Knightsbridge and Belgravia.