Tallinn is a well-known port city, a Hanseatic city and, of course, the capital of Estonia. Tallinn's Old Town is undoubtedly one of the best-preserved medieval old towns in Europe. Much of the street network and buildings date from the 13th–16th centuries, when Tallinn, then known as Reval, was an important Hanseatic city. Since 1997, Tallinn's Old Town has been a UNESCO World Heritage Site.