Ängsö is an island in the outer archipelago and the national park consists of meadows, pastures and broadleaf hills, coniferous forest, deciduous forest and arable land and reed beds. It is a valuable agricultural landscape with flowering hay meadows, pastures and pollarded trees.

Svenska Högarna is a group of islands in the easternmost part of Stockholm's outer archipelago, with a rich wildlife and barren archipelago nature.

Rörvik Nature Reserve includes most of Ramviksudden, which extends into Bagghusfjärden. The nature reserve was established in 1981 by the County Administrative Board and Norrtälje municipality manages the reserve. The area is botanically valuable and one reason for the creation of the nature reserve is the presence of some ten orchid species.

Rönnskärs udde nature reserve is located on the Väddök coast northeast of Norrtälje and consists of part of a wide headland.

Oxnäsets nature reserve is located in Rådmansby on Rådmansö and is 7.7 hectares in size. The reserve was established by the municipality in 2002 with the aim of preserving a very valuable natural forest area with plant and animal life and geoscientific phenomena.

The Fäviksgrundet nature reserve consists of the island of Fäviksgrundet, which is only about 0.5 hectares in size. The island is located about 2 miles south of Norrtälje city and is located in the inner central archipelago, near the mainland at Fäviken, in Vettershagasundet.