The Benedictine Convent of Saint John at Müstair (monastery), a World Heritage Site, was probably founded by Charlemagne, sharing history with its neighbor, the Marienberg Abbey.

A small part lies in the Italian province of South Tyrol.

The following table lists the historical language distribution of the formerly independent municipalities and also for the combined municipality: The Benedictine Convent of Saint John is both listed as a Swiss heritage site of national significance and a UNESCO World Heritage Site.

The wettest month is August during which time Müstair receives an average of 86 mm (3.4 in) of precipitation.

The driest month of the year is February with an average of 33 mm (1.3 in) of precipitation over 9.3 days.

The driest month of the year is February with an average of 34 mm (1.3 in) of precipitation over 10.6 days.

In 2009, during the International Year of Astronomy, a new public observatory Alpine Astrovillage Lü-Stailas was inaugurated.