is the oldest part of the city of Wroclaw. It was formerly an island between branches of the Oder River. The first constructions on Ostrow Tumski were built in the 10th century by the Piast dynasty, and were made from wood. The first building from solid material was St. Martin's chapel, built probably at the beginning of the eleventh century by Benedictine monks. Not long after the first cathedral was raised, in place of the small church.