Lamminsuo is one of the most notable swamps and natural sites in Vantaa. Most of the swamp area is covered by various forest swamps. In addition to these, the area features open swamplands, which make up the only larger fen in Vantaa. The west side of the lush swamp is dominated by an impressive rocky cliff. Its vertical rock wall is more than 10 metres tall. Groves grow in front of the rocky walls. The western part of the protected area is covered by a shady forest which can even feel like a pr…imeval forest in some places. A brook, Lamminsuonoja, flows through the eastern edge of Lamminsuo.
At least two species of the orchid family live in the fen; early marsh-orchid and early coralroot. The early marsh-orchid is nationally endangered, and Lamminsuo is its only habitat in Vantaa. Other rare plant species in the protected area are carnation sedge, lesser pond-sedge and downy willow. Species such as large bitter-cress, cuckoo flower, marsh violet, and greater spearwort, a flower with large yellow blooms, grow along the Lamminsuonoja brook. Some species growing in the grove on the western edge of the protected area include fly honeysuckle and spring vetchling, for example.
The remote Lamminsuo is a habitat for many animals, even though it is bordered by two large roads. Lamminsuo is a traditional winter grazing area for moose. The endangered Siberian flying squirrel has also discovered the area, which has suitable habitats for this species. Similarly, the endangered bird species rustic bunting, which is very rare in Vantaa, nests at Lamminsuo. Visitors can also sometimes hear the unforgettable singing of the red-breasted flycatcher, the quick whistles of the green sandpiper as it flies around the tree tops and the bleating courtship calls of the common snipe.