Plateau d'Assy is a small hamlet located on a small plateau west from Servoz at the foot of the Fiz Mountain range. It is a commune of Passy which lies downhill from Plateau d'Assy. The recreation area of Plaine Joux lies directly to the east of the hamlet and the D43 main road to Plaine Joux takes you through Plateau d'Assy.

Plateau d'Assy became a high altitude health destination in the early 20th century when a total of fourteen sanatoriums were built for people with tuberculosis and other respiratory illnesses. In 1970, a massive landslide hit the Roc de Fiz sanatorium killing a total of 71 people, mostly children and teenagers. A memorial has been placed on the road up to Plaine Joux in memory of the victims. The first female Noble Prize winner, Marie Curie, died in the Sanitorium Sancellemoz in 1895.

One of the main points of interests in Plateau d'Assy is the Notre-Dame-de-Toute-Grâce church. The church was built from 1938 to 1950 by Maurice Navorina with a great number of different artists contributing different parts and decorations. Its a very non-traditional church with a fascinating interior. Its definitely worth a visit.

Its location near Plaine Joux and below the Fiz mountain range, make Plateau d'Assy a great basecamp for the very popular Tour de Fiz, the trails leading to Plaine Joux and Lac Vert and Bay and Varan on the western side.