Linnansaari National Park (Finnish: Linnansaaren kansallispuisto) is a national park in the Southern Savonia and Northern Savonia regions of Finland. It lies in the middle of the lake Haukivesi, a part of greater Saimaa. The National Park was established to conserve the valuable natural features of the Finnish lakeland. On the main island there's an old croft. Field burning is still practised on its fields to protect old forms of culture. A large part of the island is natural-state coniferous forest, with some herb-rich parts. The critically endangered Saimaa Ringed Seal inhabits the park.