The fort secures the road and rail lines that pass along the lakeshore running east from Lausanne to the mountainous interior of Switzerland.

The position is an advanced work protecting the approaches to Fortress Saint-Maurice, part of the Swiss National Redoubt.

[2] The ensemble included permanent and rapidly deployable anti-tank obstacles, designed to stall or trap an enemy while the fort's weapons fired on them.

Defensive arms included two machine guns each at the Rocher de Veytaux and Montagnette, with three at Champ-Babaud, along with two 81mm mortars.

Infantry bunkers command the road and rail lines adjacent to the castle, linked to the main fort by underground galleries.

Chillon was considered for purchase by the Canton of Vaud in 1998 and was briefly opened for public tours, with the intention of making it into a museum.