Alpnach lies on Lake Alpnach, a branch of the southeastern Lake Lucerne. The municipality in the Sarneraatal consists of the districts Alpnach Dorf, Alpnachstad and Schoried. Alpnachstad is the starting point of the rack railroad that goes up Mount Pilatus. The Brünig Railway also has a station here. This narrow-gauge railroad runs from Lucerne to Interlaken Ost. The lowest point of Alpnach is the Alpnachsee (434 m above sea level), the highest point is the Tomlishorn (2128 m above sea level), a peak in the Pilatus massif. The Alpnachersee is well suited for windsurfing and is especially suitable for beginners. The hiking trails on Mount Pilatus are mostly described as easy to walk (T1). In Fräkmüntegg, the adventure park with Dragon Glider, rope park and treetop path is very popular.