Zaha Hadid’s wavy-roofed, £14.5m Serpentine Sackler Gallery opened last month to generally positive reviews, but as much of the job was the restoration of Decimus Burton’s 1820’s gunpowder magazine to which her café space appends. The muscular brick structure with Doric detailing hides another ‘room within a room’ – double-barrelled vaults that once stored powder kegs. Previously lost in the trees on an evening short-cut through Kensington Gardens, the new building’s lit up like a Roman candle courtesy of Artemide’s floor-set lighting illuminating the lily-like internal columns. This is Hadid’s first permanent building in London, and while her Marmite forms have always been hard to ignore, nay-sayers will find it difficult to just walk on by – even by night.