Heidmork Nature Reserve

Heidmork covers about thirty square kilometres of lava and lakeshore south-east of Reykjavik and was made a reserve in 1950 - at which point it was largely bare, grazed ground. What has happened since is the point: several million trees have been planted here, much of it by volunteers and school groups over seventy years, turning it into the largest area of woodland near the capital in a country that lost almost all its forest cover after settlement. Birch, spruce and pine now cover much of it. The reserve also protects the aquifer that supplies Reykjavik's drinking water, which is why some areas are restricted. Ellidavatn lake lies on its edge, and the Raudholar pseudocraters are at the northern end.

What you actually see

• A forest planted from nothing - millions of trees since 1950, largely by volunteers.
• Lava under the trees - the ground the planting had to take hold on.
• Reykjavik's water source - the aquifer the reserve also protects.
• Ellidavatn and Raudholar - the lake and craters at the edges.

When to go

May to October. Half a day.

Honest expectations

The trees are young and modest by continental standards - this is remarkable for Iceland rather than impressive in itself. Some areas are closed to protect the water supply. Roads inside are gravel and partly closed in winter. Mosquito-free, but midges gather near water.

Nearby

Raudholar is at the north end; Reykjavik is fifteen minutes away.