Wildlife and dark skies

The Esk is one of the cleanest rivers in the north of England, and its valley holds a remarkable range of habitats in a small space: ancient oak woods, hay meadows, heather moor and the sea.

The river

The Esk is Yorkshire's only salmon river. From October to December, after rain, salmon and sea trout run upstream to spawn, and the weirs at Ruswarp and Sleights are the best places to watch them leap. The river is also home to otters, seen most often at dawn and dusk, kingfishers, dippers, grey wagtails and, in the upper reaches, one of England's last populations of the endangered freshwater pearl mussel, which the national park is working to save.

The woods

Arncliffe Wood between Glaisdale and Egton Bridge and the woods around Beck Hole, Goathland and Littlebeck are ancient oak woodland, full of bluebells and wild garlic in May, with roe deer, woodpeckers, nuthatches and, in summer, pied flycatchers and redstarts.

The moors

The heather moorland above the valley is one of the largest expanses in England. It flowers from late July into September, turning the hills purple and humming with bees. Red grouse are everywhere; listen for their 'go-back, go-back' call. Curlew, lapwing and golden plover breed on the moor in spring, and merlins hunt over it. Adders bask on the paths on warm days; leave them alone and they will leave you alone.

Dark skies

The North York Moors is an International Dark Sky Reserve, and the Esk Valley, well away from the lights of Teesside and Whitby, is among its darkest corners. On a clear moonless night the Milky Way is obvious to the naked eye. Danby Beacon, the road over Glaisdale Rigg and the lane from Castleton to Westerdale are good spots; The Moors Centre in Danby runs stargazing events, particularly during the Dark Skies Festival in February. Take a red torch, warm clothes and a flask, and let your eyes adjust for twenty minutes.