Le Runesto dolmen stands on the edge of a farmed field at a high point in the landscape. This large dolmen is to be found within a large mound, where it appears to have been erected after the mound was built. Only the chamber of this passage dolmen is still accessible, by a flight of steps added in the nineteenth century.
The orthostat slabs at the back of the chamber bear engravings of axe-heads, bows, and throwing sticks. The chamber is covered by a large single capstone on which around a dozen cupules are engraved.
The excavation of the Runesto dolmen chamber by the Morbihan Polymathic Society in 1866 yielded only a few pottery fragments and a sharpened flint. The dolmen has been a listed historic monument since 1889.