St. Catherine's Monastery or the Dominican Monastery is a former monastery and one of the oldest buildings in Tallinn, the capital of Estonia. It is located in the heart of Tallinn's Old Town district full of warehouses and merchants' houses. Its remains constitute one of two remaining medieval monastery complexes in Tallinn.
A Dominican monastery is known to have existed at the site since at least 1246. The site, between present-day Vene and Müürivahe streets, was chosen carefully so as to facilitate both the friar's ability to preach to a large audience, and to suit their business interests, as they are known to have traded in fish. The monastery also had a brewery, producing four types of beer. Throughout the Middle Ages, the monastery was renowned for its scholarship.
In 1524, during the Reformation, the monastery was destroyed. Only fragments remain of the original complex. Parts have been incorporated into the Roman Catholic St. Peter and St. Paul's Cathedral, and other parts, including a finely carved portal, are visible via St. Catherine's Passage (Katariina käik), connecting Vene and Müürivahe streets.
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.