The marvelous Romanesque facade with arches and delicately carved columns is a clue to the treasures inside Lucca's cathedral, which was rebuilt in the 13th century from an earlier church. The portico was decorated in the mid-13th century with fine sculptures by Lombard artisans. In the main doorway are four beautifully carved 13th-century scenes from the life of St. Martin, by Nicola Pisano. Attached to the right side is a massive campanile, 69 meters high, of light-colored travertine and brick. Carved into the right pier of the portico is a labyrinth, especially interesting because it may predate the famous Chartres maze of the same pattern.