Beyond its beer garden, Letná is a great green plateau for a walk, a run or a sunset on the bluff, with the kinetic metronome on the old Stalin-monument plinth as a quirky focal point. The catch: it's a park, so 'nothing to do' for sights-driven travellers, and it's exposed and bleak off-season. For breathing room and a free view, it's one of the city's best assets.