Founded by the Vikings, Aalborg has developed into one of the busiest trading centers in Denmark and its fourth-largest city. Its proximity to Limfjord makes it an attractive tourist destination. Called the "little Paris of the North," Aalborg has a great atmosphere and a lot of fine old buildings. The 15th century Budolfi Cathedral - dedicated to the English St. Botolph - and the Monastery of the Holy Ghost from 1431, Denmark's oldest social welfare institution, are two of the most impressive historic sights. The old castle Aalborghus Castle (Aalborghus Slot) built in 1550 and some picturesque houses of the 17th century located in the center of the town, are not to be missed. Nearby Aalborg, you can enjoy the white beaches of the North Sea, the forest of Rold, the lovely Rebild Hills or the slopes of the Jutlandic Ridge.