Dock Tarn is a small tarn

Tarn (lake)

A tarn is a mountain lake or pool, formed in a cirque excavated by a glacier. A moraine may form a natural dam below a tarn. A corrie may be called a cirque.The word is derived from the Old Norse word tjörn meaning pond...

 located within the Lake District

Lake District

The Lake District, also commonly known as The Lakes or Lakeland, is a mountainous region in North West England. A popular holiday destination, it is famous not only for its lakes and its mountains but also for its associations with the early 19th century poetry and writings of William Wordsworth...

 National Park in Cumbria

Cumbria

Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...

, England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 at grid reference . It is situated on moorland

Moorland

Moorland or moor is a type of habitat, in the temperate grasslands, savannas, and shrublands biome, found in upland areas, characterised by low-growing vegetation on acidic soils and heavy fog...

 at 400 metres above sea level near the summit of Great Crag

Great Crag

Great Crag is a fell in the English Lake District, located near the hamlets of Rosthwaite and Stonethwaite in Borrowdale.-Topography:The higher slopes are heather-covered and quite rocky, while the lower steep slopes on the Borrowdale side are covered by a mature oak wood...

, midway between Watendlath

Watendlath

Watendlath is a hamlet and tarn in Cumbria in England.Watendlath is owned by the National Trust and sits high between the Borrowdale and Thirlmere valleys at above sea level.- Watendlath Tarn:...

, the Stonethwaite

Stonethwaite

Stonethwaite is a small village in the Lake District in the English county of Cumbria. It is situated in the valley of the Stonethwaite Beck, a side valley of Borrowdale, and within the Lake District National Park...

 valley and Borrowdale

Borrowdale

Borrowdale is a valley and civil parish in the English Lake District in the Borough of Allerdale in Cumbria, England.Borrowdale lies within the historic county boundaries of Cumberland, and is sometimes referred to as Cumberland Borrowdale in order to distinguish it from another Borrowdale in the...

. It measures approximately 300 by 200 metres, and the shoreline is indented with rocky headlands and bays. There is a tiny island in the tarn with a few small Rowan

Rowan

The rowans or mountain-ashes are shrubs or small trees in genus Sorbus of family Rosaceae. They are native throughout the cool temperate regions of the Northern Hemisphere, with the highest species diversity in the mountains of western China and the Himalaya, where numerous apomictic microspecies...

 trees growing on it. Many Lake District writers rate Dock Tarn and the walk to it very highly because of its quiet beauty.

The tarn can be reached from Watendlath by a 2.5 kilometre walk along a path that climbs very close to the summit of Great Crag; many walkers include the ascent of this fell

Fell

“Fell” is a word used to refer to mountains, or certain types of mountainous landscape, in Scandinavia, the Isle of Man, and parts of northern England.- Etymology :...

in the outing. The approach from Stonethwaite is of a similar distance but is more arduous, going steeply through the deciduous woodland in the valley before following the stream of Willygrass Gill, which is the outflow of Dock Tarn.