Quiet harborside Katajanokka is known for elegant art nouveau buildings, the gold-domed, red-brick Uspenski Cathedral and upscale seafood restaurants. Icebreakers dock on the north shore, and 19th-century warehouse Wanha Satama hosts markets and nautical exhibits. The Allas Sea Pool is a busy outdoor swimming and sauna complex. Overlooking the harbor, SkyWheel Helsinki offers panoramic views of the city.