Lake St. Moritz is the central feature of the resort — a 0.78-square-kilometre body of water that freezes solid from December to February and transforms into the venue for polo, horse racing, and cricket on ice. In winter, the White Turf horse racing festival attracts crowds from across Europe to watch thoroughbreds gallop across the frozen surface, with the Engadin peaks as a backdrop that no conventional racecourse can match.
In summer the lake thaws and becomes the domain of windsurfers and sailors. The thermal mineral springs on the southwestern shore — the town's original reason for being — feed a small spa complex at St. Moritz Bad. The lakeside promenade connects the Bad village to the main resort and makes for a flat, easy walk in either season.