Overlooking the large stream that winds its way through Hyde Park and from which the gallery takes its name, this small brick building set in Kensington Gardens is one of London's foremost showcases for contemporary art, and has featured exhibitions by luminaries such as Louise Bourgeois, John Currin, Gabriel Orozco, and Gerhard Richter. A permanent work on the gallery's grounds, consisting of eight benches and a carved stone circle, commemorates its former patron, Princess Diana. The Serpentine Sackler Gallery, a second exhibition space that's in a small Georgian gunpowder storeroom nearly, has a dramatic extension designed by Zaha Hadid as well as a stylish restaurant. If you're in town between May and September, check out the annual Serpentine pavilion, which each year is commissioned from a leading architect who is given free rein to interpret the brief—leading to imaginative results. Past designers have included Frank Gehry, Daniel Liebeskind, and Jean Nouvel.
Kensington Gardens, London, W2 3XA, England