Around the fourteenth century Olso had a population of 3,000 and was the home of King Håkon V, famous for commissioning the Akershus Castle and Fortress. In 1624, the city was destroyed in a large fire. Denmarkâs King Christian IV rebuilt it, but renamed the city Christiania. In 1925, the name was changed back to Oslo. In the 19th century, Oslo experienced many of the same changes as other large cities across Europe. Industrialisation made its mark on the Akerselva district, and the city grew quickly. The central parts of Oslo, around the Karl Johans Gate Boulevard and the Royal Palace, are simply referred to as Centrum, the centre. Noteworthy sights in this area are the Stortinget Parliament building and Oslo Cathedral. Akershus castle and fortress are located in the heart of the city right next to the Oslo fjord. Another big tourist attraction is Aker Brygge, right across the water from Akershus fortress. Here you can find restaurants, shopping malls, cosy promenade areas and the terminal for the Nesodden boats. Kvadraturen is a historical area with seventeenth century Danish buildings not far from it. Trendy Grünerløkka district at Akerselva offers some of the better bars and shops. Neighbouring Grønland is known for its colourful and multicultural range. Frogner and Majorstuen, in western Oslo, are fashionable parts of the city with shops and restaurants that attract many people.