Origin and geology The lake started as a
kettle hole (a hole formed by a
block of ice left by a retreating glacier). Various reported sounds (supposedly the pealing of a bell) could have been caused by the emission of methane. The appearance of an island (reported in 1810) could have been caused by a chunk of vegetation coming up from the bottom.
Middle Ages The lake was one of two lakes in Cumbria to appear on the
Gough Map, the oldest road map of England. It is drawn considerably larger than
Windermere, though that lake is almost forty times bigger; this can be explained, says Kathleen Coyne Kelly, following Daniel Birkholz's argument in ''The King's Two Maps'' (2004), by the political interest that underlies the Gough Map, which was used by
Edward I of England to confirm his claims to Wales and Scotland. Tarn Wadling is important (more so than Windermere) because it is connected to King Arthur, who supposedly conquered Scotland—and Edward I claimed Arthur as an ancestor. The Gough Map was a model for many others, including a map found in a sixteenth-century
commonplace book, which also singles out Tarn Wadling graphically, with "zigzagging lines evok[ing] the sharpness of its surface wave". As a fishery, its documented reputation goes back until at least the thirteenth century, when Carlisle's prior claimed a
tithe on all fish from the lake. In the early fourteenth century, John de Crumwell, keeper of the forests north of the
river Trent, allowed the Bishop of Carlisle to take fifty pike from the lake so he could restock his own ponds. Eels may have been fished as well. Later the Duke of Gloucester (the later
Richard III of England) leased the lake. The boggy area was suitable for growing
cranberries, It filled again, partly: people skated on the ice in 1939. to create farmland. It is now just a "shallow dip in the ground". which bought it in 1997. Tarn Wadling occupies 0.55 hectare, and is a rectangular area occupied by mostly mature woods surrounded by farmland; isolated from buildings and roads, it sees few visitors. The area is surrounded mostly by fences, with the remains of dry stone wall on the northwest and northeast boundaries. 2/3 of it is occupied by Scots pine, planted ca. 1880, and birch have moved in ca. 1950–1960, especially on the edges where there is sufficient light. In the southern part is an area, about 1/3 of the total property, which was planted in 1998, with Scots pine, oak, ash and cherry. Access for pedestrians and woodland managers is via an unclassified road that runs east from the
A6, near
High Hesket, toward
Armathwaite. There is room for two cars to park at the entrance to the wood, adjacent to an access gate for management. ==Folklore and literature==