The Château de Thibault de Termes was a medieval castle in the French town of Termes-d'Armagnac, in the Gers département. The keep (La Tour de Termes-d'Armagnac) is the only vestige.
Construction of the castle dates from the end of the 13th century and start of the 14th century for Jean, Count of Armagnac. The keep is 36 m (~118 ft) high and includes six levels. Strategically built on a hill which dominates the valleys of the Adour and the Arros, it allowed the d'Armagnac fanily to keep watch over the frontiers of the province of Armagnac. Its most famous inhabitant was the founder's son, Thibault d'Armagnac, companion of Joan of Arc. He gave evidence on her behalf at her trial.
Classed as a monument historique (historic monument) in 1960, the tower houses a museum of Gascon life with exhibits on regional history and culture.
The Tower of Termes d'Armagnac also belonged to the family Boingnères in particular to André Boingnères who donated the Tower in the 1960s, so that this historic important heritage can be opened to all, an objective innovating for time .