Maridalen protected Landscape in Oslo, Norway. The landscape conservation area is part of Nordmarka, and forms a wide valley in the north of Oslo municipality with the Maridalsvatnet lake as a natural center. The area is a well-defined landscape where the mosaics of forests, fields, meadows, pastures, river runs and water form a whole landscape. This provides a rich diversity of vegetation types. Both agricultural and forestry operations are carried out in the valley, which has 15 farms.

The trail and trail network is well established, and it is easy to get there from the fjord to the top. There is also a natural and cultural trail in the area. Maridalsvannet is the main source of drinking water for Oslo.