Allée couverte de l'Île-Grande, gallery grave in Pleumeur-Bodou, France

The Allée couverte de l'Île-Grande is an east-west gallery grave 8.50 m long and 1.60 m wide, set in the centre of Île-Grande. Its chamber is edged by four upright slabs on the north side and five on the south, 1 to 1.40 m high, and roofed by two capstones: one 4.50 m by 2.50 m and 0.50 m thick, the other 3.50 m by 2.50 m and 0.25 m thick. Closely set tall slabs surround the monument.

The Allée couverte de l'Île-Grande was excavated in 1866, 1868, 1909 and 1910; the finds, four polished axes, flint flakes, black pottery sherds, a bronze disc and an iron object, are now lost. The monument was classified as a historic monument on 23 January 1956. Jean L'Helgouach described a vestibule on the north side, with two slabs and a pillar narrowing the passage to 1 m, no longer visible.

Local legend makes the tomb the home of the C'horrandoned, dwarf women who danced with passers-by on full-moon nights. They told pregnant women whether the child would be a boy or a girl and whether the birth would be easy. If weather kept them from dancing, they made travellers recite the days of the week quickly, but saying Sunday made the imprudent disappear.

The site sits about 115 feet (35 meters) above sea level and is accessible from nearby roads with open access during daylight hours and no security barriers. Visitors should handle the ancient stones respectfully by avoiding climbing on the structure or disturbing it, as the fragile monument requires protection from damage.

The Breton name Ty-ar-C'horrandoned links the tomb to the C'horrandoned, the dwarf women of local legend said to live here. On full-moon nights they danced with passers-by and told pregnant women whether the child would be a boy or a girl and the birth easy or hard. When weather kept them from dancing, they made travellers recite the days of the week quickly, but never Sunday, or the careless vanished.