Timmermalm nature conservation area is in Askisto city district, close to the Espoo border. The conservation area's landscape is dominated by the rock ridge reaching from north to south, the hillside spruce forests surrounding it and the narrow swamp on the western edge of the area.
The swamp area's north end has a beautiful black alder swamp. The swamp area follows the south-flowing brook as a narrow strip. There is also a small open swamp in the southern part of the swamp area.
Common hazel …bushes grow in the southernmost part of the protected area.
The conservation area's open rock areas are habitats to rock campion and red Alpine catchfly, which are both rare species in southern Finland. Large ferns, such as ostrich ferns and lady ferns, add lushness to the forest landscape of the black alder swamp in the northern part of the area.
In addition to the forest swamps and various boreal forests, the Timmermal nature conservation area also has some groves. Liverworts and wood anemones bloom in the grove areas. Some individual small-leaved linden trees grow at the bottom of the steeply inclining west-facing hillside. The hillside forests with the open rock areas are popular green areas among the local residents.
Timmermalm is one of the best Siberian flying squirrel habitats in Vantaa. Most frequently they move around the mixed coniferous forests at the western edge of the conservation area, where aspens, birches and other deciduous trees grow in addition to spruce. The unbroken forest zone continues all the way to Nuuksio National Park, so sometimes bigger animals, such as moose and white-tailed deer, can be spotted at Timmermalm. The most common birds in the area include thrushes as well as smaller species, such as tits, goldcrests and willow warblers. Hazel grouses and crows also nest in the area.
The Timmermalm nature conservation area was protected in 2006. The size of the protected area is 68.4 hectares. The conservation area has walking paths, but they are unmarked.