The first written mention of Stockholm dates from 1252, when a powerful regent named Birger Jarl build a fortified castle and city here. King Gustav Vasa took it over in 1523, and King Gustavus Adolfus made it the heart of an empire a century later. But by the beginning of the 18th century, Swedish influence had begun to wane, and Stockholm s development had slowed. It did not revive until the industrial Revolution, when the hub of the city moved north from the Old Town area. Nowadays most Stockholmers live in high-rise suburbs dotted in pine forests and by lakesides around the capital, linked to it by a highly efficient infrastructure of roads, railways, and one of the safest subway systems in the world.
Air pollution is minimal and the city streets are relatively clean and safe.