The city of Helsinki, on the tip of southern Finland, was founded in 1550 on orders of the Swedish king Gustavus Vasa. Surrounded by water on three sides, Helsinki was one of the world's first planned cities and is noted for its 19th-century neoclassical architecture. Because the city is relatively compact, most of it can be explored on foot. Helsinki has a number of unique and interesting churches to explore. The Lutheran Cathedral stands in neoclassical grandeur over Senate Square, while the red-brick Uspenski Orthodox Cathedral brings a touch of Russia to the city. The tall spires of the Johanneskirkko are prominent on the skyline. And then there is the Rock Church — a fascinating feat of modern architecture built almost entirely underground.