The Church of St. Nicholas is a cross-domed basilica dating perhaps to the 8th or 9th century. It was built over the ruins of a large Justinianic church following devastating Arab raids in 7th and 8th century. The church became an important pilgrimage center, leading to it being significantly restored and redecorated in the 11th and 12th century. However St. Nicholas's relics were stolen by Italian sailors in 1087 and transferred to Bari. It was subsequently covered with several meters of alluvial deposits. In the 19th century, the main vaults were reconstructed and a small chapel was built on the southwest corner.