Lej da Staz (Lake of Staz in Romansh) is a small high-altitude lake east of the resort, surrounded by larch and Swiss pine forest. At 1,822 metres, it sits in a natural hollow that collects cold air, and the trees around it are often frosted when the resort above is sunny. A circular walking path takes about 45 minutes and passes through forest that feels genuinely wild by Alpine standards.
The lake is popular with cross-country skiers in winter, who loop it from the Staz forest trails connecting St. Moritz to Pontresina. In summer it becomes a swimming spot for locals — cold even in August, clear to the bottom, and usually uncrowded by the time most visitors have drifted toward the lake promenade.