The Tees-Exe line is an imaginary line that can be drawn on a map of Great Britain

Great Britain

Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...

 which roughly divides the lowland and upland regions of the country.

The line links the mouth of the River Tees

River Tees

The River Tees is in Northern England. It rises on the eastern slope of Cross Fell in the North Pennines, and flows eastwards for 85 miles to reach the North Sea between Hartlepool and Redcar.-Geography:...

 between Redcar

Redcar

Redcar is a seaside resort in the north east of England, and a major town in the unitary authority of Redcar and Cleveland in the ceremonial county of North Yorkshire. It lies east-northeast of Middlesbrough by the North Sea coast...

 and Hartlepool

Hartlepool

Hartlepool is a town and port in North East England.It was founded in the 7th century AD, around the Northumbrian monastery of Hartlepool Abbey. The village grew during the Middle Ages and developed a harbour which served as the official port of the County Palatine of Durham. A railway link from...

 in the north east of England with the mouth of the River Exe

River Exe

The River Exe in England rises near the village of Simonsbath, on Exmoor in Somerset, near the Bristol Channel coast, but flows more or less directly due south, so that most of its length lies in Devon. It reaches the sea at a substantial ria, the Exe Estuary, on the south coast of Devon...

 in Devon

Devon

Devon is a large county in southwestern England. The county is sometimes referred to as Devonshire, although the term is rarely used inside the county itself as the county has never been officially "shired", it often indicates a traditional or historical context.The county shares borders with...

, the south west. The lowlands (sedimentary rock

Sedimentary rock

Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....

s) are predominant to the east of the line and higher land (igneous

Igneous rock

Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...

 and metamorphic rock

Metamorphic rock

Metamorphic rock is the transformation of an existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and pressure causing profound physical and/or chemical change...

s) dominates to the west.