| Upper Teesdale | |
|---|---|
 Monk's Moor, Upper Teesdale SSSI | |
  Site of Special Scientific Interest | |
| Location | MAGiC MaP |
| Nearest town | Middleton-in-Teesdale |
| Coordinates | 54°41′N2°16′W / 54.683°N 2.267°W /54.683; -2.267 |
| Area | 14,035.6 ha (54.192 sq mi) |
| Established | 1951 |
| Governing body | Natural England |
| Website | Upper Teesdale SSSI |
Upper Teesdale is aSite of Special Scientific Interest (SSSI)[1] in the westCounty Durham,England. It encompasses an extensive upland area that includes theheadwaters of theRiver Tees and the surrounding catchment area upstream of the village ofLangdon Beck.
The site has a diverse mix of habitats, mainly dryheath, with wet heath andblanket mire in areas that are poorly drained.
The Upper Teesdale SSSI is one of the most important botanical sites in Britain;[2]the flora is exceptionally rich in species that are nationally rare, including some that arerelicts of the arctic-alpine environment of thelast glacial period. The area supports internationally important populations of somewading birds and is home to several rareinvertebrates. Within the SSSI are several locations that are of national importance geologically, including one of only two known outcrops of 'sugar'limestone in Britain.[2]
The southern part of the SSSI largely coincides with the eastern portion of theMoor House-Upper TeesdaleNational Nature Reserve, which has been designated a 'Biosphere Reserve' byUNESCO. The entire area falls within theNorth PenninesArea of Outstanding Natural Beauty.
Much of Upper Teesdale SSSI was formerly designated as Upper Teesdale and Appleby Fells SSSI. Following a substantial revision in 1990, most of the site was divided between two new (but adjoining) SSSIs, Upper Teesdale in Durham andAppleby Fells inCumbria. A small part was amalgamated withMoor House National Nature Reserve to form a third SSSI,Moorhouse and Cross Fell, which is contiguous with the other two. At the same time, two further SSSIs, Mill Beck Wood and Moking Hurth Cave, were incorporated into Upper Teesdale SSSI and ceased to exist as separate entities.
Part of the land within Upper Teesdale SSSI is owned by theMinistry of Defence[3] as it includes part of theWarcop Training Area.