The Château de Lacoste or La Coste is a ruined castle in the commune of Lacoste in the Vaucluse département of France.LocationThe castle is sited on an extension of the northern flank of the Little Luberon on which the village stands. This position offers its occupants superb views over the valley of the Calavon, the Monts de Vaucluse, Mont Ventoux and the Alps, as well as the village of Bonnieux which can be seen on a neighbouring hill.HistoryThe castle's origins are in the 11th century, but it was largely modified in subsequent centuries.It was for many years the property of the Simiane family.Two hypotheses are suggested for the transfer of the castle from the Simianes to the Sades. In 1627, Diane Simiane married Jean-Baptiste de Sade, ancestor of the Marquis de Sade, who thus became owner of the estate. In 1716, Isabelle Simiane bequeathed the castle to her cousin Gaspard François de Sade, Lord of Saumane and Mazan. This latter hypothesis is the most probable. The Marquis de Sade stayed there from 1769 to 1772, between the scandals at Arcueil and Marseille, then after the latter and his flight to Italy, he took refuge there until his incarceration in the Château de Vincennes in 1777. Escaping while being transferred to Aix, he took refuge there for the last time from 16 July to 7 September 1778 before being returned to Vincennes.