The four-towered Savoy castle sits squarely on Yverdon's main square, an unmissable mass of pale stone with red-tiled conical roofs. It was built in the 1260s by Peter II of Savoy as part of his ring of fortifications around Lake Geneva, and the basic medieval shape has survived intact — a rare thing for a town castle so often demolished or rebuilt elsewhere.
Inside, the castle now houses the Musée d'Yverdon et région, with collections covering Roman Eburodunum (Yverdon's predecessor), medieval life, and Pestalozzi's educational reforms. The exhibits are modest but the building itself is the main attraction: thick stone walls, vaulted ceilings, and rooftop access via the south-east tower with views over the lake and the Jura.