Lanleff’s temple is a pink sandstone ruin located in Lanleff, Brittany. It is a round church, reminiscent of the Church of the Holy Sepulchre in Jerusalem. Commonly called "Temple Lanleff", this building with two circular enclosures is one of the oldest monuments of the Middle Ages in Cotes d'Armor and one of the most enigmatic. Prosper Merimee, as inspector of historic monuments, visited him in 1836 and contributed to its designation as a historic monument. This building, in Romanesque style consists of a sleek central nave consists of twelve semicircular arches, supported by pillars resting on a solid foundation wall. The stones that constitute them are relatively friable sandstone and a variety of volcanic rock called "spilite". The outer wall, which remains only a part, has openings designed as deadly. Most bases of columns and their capitals are adorned with decorations inscribed in stone, most often geometric shapes but there are also human and animal figures. These decorations, very crude and degraded, appear before that we know of 11th and 12th centuries. This building, which has just been restored under the aegis of historical monuments, the charm and serenity.
