Korouoma is about 30 kilometres (20 mi) long, few hundred meters wide and up to 130 m (430 ft) deep canyon at Posio, Finland. The entire area is natural reserve. At the bottom of the canyon there's Korojoki River, which ends up to Kemijoki River. There are plenty of spiecies in varied nature of Korouoma. Some of species found are rare. Korouoma offers great opportunities for hiking, watching the nature, fishing and reviewing the cultural history of usage of nature at the area.
Korouoma is fairly popular hiking area. There is a marked hiking path at the bottom of the Korouoma and several fireplaces, huts and cabins. Finnish Administration of Forests takes care of the routes and hiking related infrastructure there.
Part of Korouoma's distinctive nature are the cliffs both sides of it, where several streams freeze during the winter forming huge ice formations. Because of these ice formations Korouoma is known as the best ice climbing location in Finland. There are some climbing routes that can be used during the summer time as well.
Something I learnt: when they tell you that there are many mosquitoes in Lapland during the summer, the are understating it.