Solid church in granite built inside the medieval town walls. Work began in 1488 under the guidance of Biscay master Tomé de Tolosa, and using parts of a primitive Romanesque chapel (remains are visible in the north side); it pursued slowly, until the completion of the tower of the main façade in 1556. Important architects involved in the construction include João de Tolosa and Pero Galego. Inside, the building is a basilica with main nave and two aisles, and is notable for its inlaid ceiling (1565) showing oriental influences. The Mareantes Chapel, built by the corporation of seafarers, is one of the earliest renaissance works in Portugal. The church was classified as a National Monument on June 16, 1910.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.