Åsnen was made a national park in March 2018, which means that the nature in the surroundings is unique and of international interest. The national park is about 1,868 hectares large, and 75% of the area is water. The main entrance is situated by the bridge Sunnabron near the narrow that leads to the largest island in Åsnen, Sirkön. Hiking paths leads to Bjurkärr. Bjurkärr has one of Sweden’s most valuable broad-leaved deciduous forests, since it is very rich in species. The bird life is rich and you can find unusual insects, moss and lichen here. The other entrance to the national park is situated by the left shore of Åsnen and near the mountain Trollberget. Here you can find leaflets about the national park and also both broad-leaved deciduous trees and conifer trees such as pine and fir trees. Additionally, there is a shore by the lake and wetland forest, all in the same small area. Some places in the national park have toilets, fire places and resting places. Some have paths marked with different colours and a wooden deck near the lake where you can unpack your basket with Swedish fika and just enjoy the view of Åsnen, with all its lakes and water.

Steinwache Memorial and Museum is a museum that documents persecution and resistance during the Nazi regime. Established in a former police station that, under the Gestapo, was known as "West Germany’s Hell" because of the torturing of the opponents of the Nazi regime. The museum exhibits documents, photographs and even the interior of the prison cells to give an impression to its visitors.

While Colossal Cave is this park's centerpiece, it is certainly not its only attraction. It is also home to museums, various species of animals, public trails, a butterfly garden, as well as camping and picnic areas. Some special events are organized during the year, like birding or walking tours.