Tombeau de Merlin, Megalithic burial site in Paimpont Forest, France.

Tombeau de Merlin is an ancient gallery grave built with purple schist stones positioned in a linear arrangement. The structure sits within Paimpont Forest and shows signs of its long history, with some original stones still standing after centuries of weathering.

In 1820, judge J. C. D. Poignand claimed Merlin was buried in the Forest of Paimpont, prompting twenty years of treasure hunting by locals. In 1889, Félix Bellamy fixed the tomb's location on this gallery grave, which originally comprised two gallery graves, one called the Tomb of Viviane. In 1892, grave robbers destroyed most of the stones, leaving only three by 1894.

The name comes from a 19th-century tradition linking this ruined gallery grave to Merlin; Félix Bellamy fixed the identification in 1889. Visitors still leave flower wreaths and papers bearing wishes in the centre of the monument, and ashes of the dead have sometimes been scattered there. The Fontaine de Jouvence lies on the same "Enchanter's Loop" footpath.

The site sits in a forest setting and is best visited during daylight hours to see the stones clearly and navigate safely. Access can be limited during hunting season from September through March, so planning a visit outside these months works better.

Félix Bellamy recorded two gallery graves here, the second called the Tomb of Viviane. The only known images of the monument before its destruction are two 19th-century engravings and a photograph he took in 1899.