Visby is located in the western part of Gotland, on the Baltic Sea. It is a UNESCO World Heritage Site, surrounded by a ring of 12th-century defensive walls with well-preserved gates and fortified towers. In Visby there are about two hundred historic stone buildings and narrow cobblestone streets that contribute to Visby's unique atmosphere. In the summer, during the Medieval Week, there are tournaments, festivals and fairs referring to the Hanseatic traditions of the largest town of Gotland. Visby is also known for rose bushes, which can be seen almost everywhere.