Margaret Island is the best idea Budapest ever had with a sandbar: two and a half kilometres of car-free park dropped in the middle of the Danube, equal parts lawn, ruin and spa. The walk runs its full length, south to north.
About four and a half kilometres, best on a mild afternoon. Cross from the Margaret Bridge tram stop to the southern tip and the musical fountain, which performs on the hour to a crowd on the steps. Follow the rubberised running track north under the planes — the city's open-air gym, and the simplest line through.
Halfway up come the Dominican convent ruins, where Margit (Margaret), the king's daughter promised to God, lived and died; her grave slab still lies among the roofless walls. On past the white iron water tower of 1911, a lookout with a summer theatre at its foot, to the small Japanese garden and its warm-spring pond.
Leave at the northern end onto Árpád híd, tram 1 and the M3 waiting. Look back: two kilometres of green, and no cars at all.