This cylindrical monument dating from the late 12C and finished by a cone is home to two rooms. One is on the ground-floor, the other is in the conical section and was oddly inaccessible. Many hypotheses have circulated regarding this paradox: was it a tower built in honour of Saint Bernard, who was said to have blessed bread in Sarlat, thus miraculously curing the sick in 1147, or was it a lantern of the dead (a hole in the cupola of the ground-floor through which a lantern could be passed) or was it a funerary chapel? The mystery remains.