Immense white tongues seem to push forth from the ice and snow-covered Piz Palü and Piz Bernina towards Pontresina. These are the Pers and Morteratsch Glaciers. At the Isla Persa, the two glacier arms unite to form a glacier tongue which ends after barely two kilometres. Only 120 years ago, the Morteratsch Glacier extended nearly 2 km further into the valley. An educational trail informs hikers about the retreat of the glacier and the mysterious life that exists in the pre-glacier ridge. From mid-June to the end of September there is a guided tour every Monday morning.