Linnaistensuo Nature Reserve is a representative sample of the Päijärvi Nature Reserve.
The swamp is surrounded by a fairly old forest with fir trees, but the lingonberry pine-dominated forest also grows on the campus. The area is flat, with most of the surrounding forests only a few meters higher than the swamp level. The most prominent hill is the Linnaistenmäki hill, which rises in the eastern part of the protected area and is thirty meters above the central part of the swamp. The mound was dug with gravel.
