In Norrtälje municipality you will find Ängsö National Park, which was established in 1909 and is Sweden's oldest national park. Ängsö is an island with a well-preserved agricultural landscape from the 19th century and is located in the inner archipelago east of Bergshamra. The island has hay meadows, natural pastures and an old farm environment.

The park is important as both a cultural heritage site and a reminder of old farming methods, but it is also known for its idyllic archipelago environment with fantastic flowers in spring. There is also an exhibition about the national park in the picnic shelter at the pier and a nature trail. 

You can visit Ängsö all year round, but the island can only be reached by boat. During spring and summer there are boat trips from Stockholm almost daily and you can also visit the island with your own boat and dock at the guest jetty or by taxi boat. The nature conservancy on the island offers guided tours daily.

Ängsö National Park is located in Norrtälje municipality, but the land is owned by the state and the national park is managed by the County Administrative Board.