Forest bathing at Castle Eden Dene

Castle Eden Dene is a National Nature Reserve on the edge of Peterlee: a gorge 3.5 miles long, carved by meltwater after the last ice age. Its steep sides are soft magnesian limestone, and Natural England describes its woodland of yew, oak and ash as a survivor of the wildwood. It is the largest of the coastal denes between Sunderland and Hartlepool, reaching the sea at Denemouth, and holds over 450 plant species. The Castle Eden Burn often runs dry in summer, sinking into the rock.

Start from the car park at Oakerside Dene Lodge in Peterlee. A short easy-access path begins there; beyond it, about 12 miles of mostly waymarked footpaths run through the dene. These are steep and muddy in places and can be slippery, so boots are a good idea. Look out for roe deer. Cycling and riding are limited to one marked route, so the rest of the dene is for walkers.