Grainau lies at the foot of the Zugspitze in the Wetterstein Mountains. It is part of the seven municipalities of the former County of Werdenfels, along with Garmisch-Partenkirchen, Farchant, Mittenwald, Krün and Wallgau. Grainau is also home to two mountain lakes, the Badersee and the Eibsee. Waxenstein mountain sits to the south, while the Kramerspitz mountain and Ammergau Alps sit to the north.