Festningsalmenningen is a park that acts as a green connection between Kvadraturen, Bjørvika and the seafront. The area is designed as a park-like extension of Grev Wedel's Plass and the Fortress, and aims to strengthen the city area through new footpaths. Rows of trees in the common area are extended towards the sea front, which contributes to a more coherent urban space.
Since 2017, the temporary project SALT has been part of the Fortress Commons, and the area has been developed with pavilions as an integral part of the park. The public also gives access to cultural activities in the local area, including the Contemporary Museum and the Astrup Fearnley Museum. This creates a natural transition between Bjørvika and Revierhavna, and promotes active use of the area.