Château de La Coste, Protected castle in Grézels, France.

Château de La Coste is a ruined castle in Grézels, built of light grey ashlar masonry. Its square plan is flanked by two massive square towers to the west and two round towers to the east, with a rectangular corps de logis, two wings and a south curtain wall enclosing the courtyard. The north wing, once stables, was quarried for stone and fitted with an open gallery.

Bernard I Guiscard received the castle as a fief from Guillaume de Cardaillac, bishop of Cahors, for his part in the Albigensian Crusade; an act of 1267 confirms the grant. In 1348 Philippe VI stationed a garrison there, the first time the site is called a castle. The present building was rebuilt at the start of the Hundred Years' War, and in 1580 Protestant troops took, pillaged and partly destroyed it.

The Guiscard family, vassals of the Bishop of Cahors, held La Coste from the 13th century and remained Catholic during the Wars of Religion; Jean III backed the Ligue, which led to the castle's capture and partial destruction by Protestant troops in April 1580. The name La Coste refers to the hillside site above Grézels.

The castle is privately owned and closed to the public, so it can only be seen from outside; do not plan on entering. It stands on a slope among trees in Grézels, in the Lot. The building was listed as a monument historique in 1961.

The original sandstone blocks are still visible and show the craftsmanship of medieval stonemasons. The way these stones were cut and fitted together reveals much about building techniques from that era.