Slottsskogen is Gothenburg's largest park — 137 hectares of forest, meadows, and ponds with free entry all year. The park runs along a ridge west of the centre and contains several things you would not expect to find in a city park: a free zoo (penguins, elk, seals, and a petting area with farm animals), a children's miniature railway, an old observatory, and the Natural History Museum at the eastern entrance.
The Natural History Museum's collection includes the Malm Whale — one of only two fully mounted blue whale specimens in the world (the other is at the Museum of Natural History in Geneva). The whale is displayed in a dedicated hall with its jaws open, and visitors can look into its mouth. There is also an extensive mineral collection and exhibits on Swedish natural history.
The park itself is good for walking and running year-round. In summer, the café terraces near the main entrance are popular; in winter, the park is quieter but still pleasant on a clear day. Free entry to both the park and the zoo.