Tyresta

Tyresta National Park was established in 1993 some twenty kilometres from the centre of Stockholm and protects some 20 km², themselves surrounded by a much larger nature reserve. It is one of the best-preserved natural areas in central Sweden and, at the same time, one of the most accessible from a large city.

Its main asset is the forest: Tyresta preserves the largest area of primeval forest left south of the river Dalälven. It consists of old pine woods of twisted, gnarled trees alongside tall spruces, with abundant standing and fallen deadwood, hollow trees and natural regeneration, a combination that supports a diversity of species dependent on old wood far greater than that of any worked forest.

The relief is one of narrow fault valleys and bare crags between which lakes and peat bogs are set, a landscape typical of Stockholm's inner archipelago. In 1999 a large fire affected part of the park, and the burned area has been left to develop without intervention: the result is an open-air laboratory on ecological succession after fire, with beetle and fungus species specialised in burned wood that appear only in these conditions. Beside the park, at Tyresta by, the national information centre for Sweden's national parks operates.