It is situated in North European continent, Norway. Oslo is one of the famous cities of Norway that gained its popularity out of working very hard to reduce pollution. In fact, it encouraged many governments in the world who were also fighting the issue of pollution in their cities. Due to its clean environment, Oslo is described as one of the most expensive cities in the world. Accommodations and food is also very expensive. Readers digest ranked it as the most loveable city and the second greenest in 2007. Some of its tourist attraction includes large number of sites and parks and museums which earns Norway foreign exchange.