Oslo is the capital of Norway and the country's largest city, with a population of over 650,000 inhabitants. It is a compact capital city surrounded by the Oslo Fjord on its south side and the nationally protected forest Marka to its east, north, and west. Oslo is an important centre of Norwegian trade, banking, industry, and shipping. It is also a major cultural centre, with many museums, theatres, and concert venues. Some of the most popular tourist attractions in Oslo include the Royal Palace, the Oslo Opera House, the Viking Ship Museum, and the Vigeland Sculpture Park. Oslo is a relatively green city, with many parks and waterways. The city is also known for its clean air and water, and its commitment to sustainability. Oslo is a popular destination for tourists from all over the world and is consistently ranked as one of the most liveable cities in the world.