Bornholm is an island in the Baltic Sea that belongs to Denmark and is strategically located south of Sweden, north of Poland, northeast of Germany. The ruins of Hammershus, the largest medieval fortress in northern Europe, testify to the strategic importance of the island. The island's population is mainly engaged in dairy products, crafts, and arts, primarily glass and pottery. During the summer months, the island is a tourist attraction that attracts visitors from all over the world.