The Château Royal de Blois is one of the finest examples of French royal architecture in the Loire Valley, with four distinct wings representing four centuries of building — medieval, Flamboyant Gothic, early Renaissance, and Classical — all arranged around a single courtyard. Four French kings lived here, including François I, whose famous open spiral staircase is the centrepiece of the Renaissance wing.
The most striking room is the study of Catherine de Medici, where 237 carved wood panels conceal hidden cupboards — popular legend claims they once held poisons, though historians are sceptical. The château also houses a fine arts museum with paintings and royal portraits. The son et lumière show projected onto the façade on summer evenings is worth timing your visit around.