The fascinating facade of the chapel dates from the 12th century. Like Le Puy Cathedral, its multicolor stonework and arches give it an exotic appearance revealing Islamic influences. The stonework of the facade illustrates themes from Genesis and Revelation. The reliefs within the unusual trefoil arch depict the Lamb of God (labeled with AGNUS DEI) in the center, with four Elders of the Apocalypse holding vials of perfume on each side. Above the arch are vines populated with birds and two human figures, which probably represents Creation and the Fall. Note the tiny Green Man masks beneath the feet of each human figure.
Under the arch are more vines, which issue from the mouths of large human heads and contain birds pecking at grapes. This is thought to symbolize Creation and Redemption, but the Parable of the Mustard Seed has also been suggested. The lintel is carved with two mermaids: one with a snake's tail and one with the tail of a fish. These might represent temptation or the souls who have died on land and at sea. The capital on the right has twin images of a man entwined in foliage and holding plants, while the left capital depicts two eagles in the pose of phoenix. Again Creation and Redemption seem to be represented.