This powerful circular keep some 40m/131ft high was built from 1240 to 1249. The small entrance tower and bridge linking it to the ramparts date from the 16C. Templars and rebels accused of treason were imprisoned here, but it was from the Revocation of the Edict of Nantes (1683) that Constance Tower was at its busiest, playing "host" to Huguenot prisoners. From the terrace, the view stretches over the salt marshes, Camargue, pyramids of La Grande Motte, Sète and the Cévennes.