Château du Marais, French castle in Le Val-Saint-Germain, France

Château du Marais is a three-story stone building in Le Val-Saint-Germain, its pale yellow facade marked by a central portico of four colossal Doric columns under a triangular pediment. A large slate dome with a lantern and two round windows rises above the center, while a gray mansard roof with dormers tops the repeated tall windows. A low terrace and iron gates run along the front, beyond a shallow pond.

Jean Le Maître de La Martinière, treasurer general of the Artillery and Engineers, bought the estate in 1767 and had the old building demolished in 1772. Architect Jean-Benoît-Vincent Barré built the present château between 1772 and 1779; the owner reportedly destroyed the old materials to be sure of having everything new. The cost and splendour astonished contemporaries.

The château's name comes from the marshes drained by the monks of Vaux-de-Cernay in the 12th century. Boni de Castellane, who owned it around 1900, described in his memoirs entering through the middle of the courtyard, with the salon d'honneur at the centre of the plan, preceded by plain rooms and followed by richer ones. The Talleyrand and Chateaubriand museums and the orangery are no longer open to visitors.

The château, its French formal gardens, the Talleyrand and Chateaubriand museums and the orangery are no longer open to visitors. The building stands on the eastern edge of a platform ringed by water-filled moats, with the Rémarde feeding the large pond in the park. It lies in Le Val-Saint-Germain, near Saint-Chéron, about 36 km southwest of Paris.

The square dome above the entrance portico copies the design of the Pavillon de l'Horloge at the Louvre. On the garden side, the same feature becomes a flattened pavilion roof and the columns give way to composite pilasters, so the two facades read very differently.