Fontaine Saint-Aubert, Medieval fountain at Mont-Saint-Michel, France

Fontaine Saint-Aubert is a stone water source on the northern side of Mont-Saint-Michel, featuring a conical tower with an ogival roof. The structure includes a paved area and was once connected to the monastery by a protected stairway.

The spring was already honoured with a structure in the 8th century, and according to legend Saint Aubert found fresh water here after praying for a source. In the 13th century the fountain was fortified with a defensive tower and linked to the monastery by a Grand Degré protected by high walls, whose ruins remain in the Petit-Bois. The present shelter dates from 1757, and the spring dried up in later times. It was classified as a monument historique on 29 December 1908.

The name refers to Saint Aubert of Avranches. According to legend, Aubert prayed for a spring because Mont-Saint-Michel had neither well nor cistern; an angel then pointed to a stone from which water flowed. Later the water was said to have healing properties.

The site is located on the northern side and is accessible by foot along Mont-Saint-Michel's pathways, though the surfaces are uneven. Visit during drier periods, as the area can become slippery in rain.

The fountain's name honours Saint Aubert of Avranches, the bishop linked to the legend of the spring. The fortified tower that once protected it survives only as ruins, and the stairway from the monastery was guarded by high walls whose remains can still be seen in the Petit-Bois.