Chapelle Notre-Dame-de-la-Merci de Planès, Romanesque church in Planès, France

The Chapelle Notre-Dame-de-la-Merci de Planès is a small Romanesque church in Planès, near Mont-Louis in the Pyrénées-Orientales. Its walls form an irregular circle set within an equilateral triangle, with three semicircular apsidioles at the corners. The central ovoid dome rests on round arches and small squinches above niches in three supporting piers. Outside, a cylindrical tower with a conical tiled roof hides the dome, topped by a square belfry with two round-arched openings holding bells.

The church is first documented in 1442, though specialists today date the building to the 11th century; its promoter was the abbot Oliba. Locals called it Mesquita, "mosque" in Catalan. In the 19th century Romantics linked it to the 8th-century chronicle of the Anonymous of Córdoba, making it the tomb of Munuza, killed in 729. It was classified a monument historique in the 1840 list.

Locals long called the building "Mesquita", Catalan for mosque, though the reason is unrecorded. The name Notre-Dame-de-la-Merci refers to Our Lady of Mercy. A polychrome wooden Virgin of the 12th or 13th century, close in style to those of Odeillo and Err, is kept here; legend says it was hidden at the approach of Saracen raiders and found again by a bull.

The church stands in the village of Planès, near Mont-Louis in the Pyrénées-Orientales, so it is reached on foot within the village rather than by mountain trail. The entrance is the arched wooden door in the western angle of the building; an earlier doorway appears to have been in the western absidiole. The thick rendering over rough rubble masonry leaves few datable features on the exterior.

The church was long known locally as Mesquita, Catalan for "mosque", a name that fed 19th-century Romantic speculation linking it to the 8th-century Muslim presence in Cerdanya. The Romantics even made it the tomb of Munuza, the Berber chief killed in 729, said to have been raised by Lampégie, daughter of Duke Eudes of Aquitaine.