Stockholm is the capital of Sweden located on the Baltic Sea. It has a population of 820,000 residents within an area of 209 square kilometers, 40% of which consists of parks and recreational areas. Public transportation in Stockholm is highly developed, with 90% of residents living within 300 meters of frequent service. The city also encourages biking and walking through extensive bike lanes and by being compactly designed across 14 islands. Stockholm has implemented various policies and initiatives to become one of the world's most sustainable cities, such as a congestion tax, clean vehicles, renewable energy powered public transit, and an innovative waste management system.