Located by the sea, Helsingborg has historically been the gateway to Denmark and the rest of Europe since it is only 4 km of water between Helsingborg and its Danish sister city Helsingor. Surnamed the Pearl of the Sound it is a town striving to be continental and something else than the rest of Sweden. Helsingborg is known for the Karnan Tower, the remainder of a medieval fortress. A trip to Sofiero is a must, particularly in May and June when the rhodendendron is in full bloom. Fredriksdal museums and gardens is one of Sweden's most famous open-air museums with an outstanding botanical garden. The Karnan tower, Helsingborgs most famous landmark, has guarded the city for over 600 years. The Dunker Culture center displaying various temporary exhibitions along with objects from the town's museum collections.