The current village of Sainte-Agnès is dominated by a medieval castle located between 2,385 and 2,509 ft (727 and 765 m) above sea level on a rocky outcrop. It forms a narrow and steep space on which the castle and the village coexisted from the 11th to the 15th centuries. The fortress' central tower and church date from the beginning of the 11th century. Between the end of the 12th and the beginning of the 13th centuries, they were supplemented by a set of fortified buildings, an enclosure, and residential houses. Other development works carried out in the 14th century allowed the castle to acquire its current appearance and serve as a defensive fortress on the border of the County of Provence.