The city of Stockholm is spread out over 14 islands situated at the mouth of Lake Mälaren by the Stockholm archipelago, where the Swedish mainland meets the Baltic Sea. Due to the abundance of waterways, Stockholm is sometimes referred to as Venice of the North. Since Stockholm has virtually no heavy industry it is one of the world's cleanest metropolises. Roughly 85% of its residents work in the service industry.
After Copenhagen, Stockholm is the most visited city in the Nordic countries with about one million tourists arriving each year.