The château fort de Lourdes is a historic castle located in Lourdes in the Hautes-Pyrénées département of France. It is strategically placed at the entrance to the seven valleys of the Lavedan. Since 1933, it has been listed as a monument historique by the French Ministry of Culture.
Besieged in 778 by Charlemagne, it became the residence of the Counts of Bigorre in the 11th and 12th centuries. In the 13th century, it passed into the possession of the Counts of Champagne, part of the kingdom of Navarre before coming under the crown of France under Philippe le Bel. It was ceded to the English by the Treaty of Brétigny in 1360, before returning to France at the start of the 15th century after two sieges. In the 17th century, the castle became a royal prison, and then a state prison after the French Revolution. It continued in this role until the start of the 20th century, when it became the Pyrenean Museum which it remains.