A geological dividing line cuts across Devon roughly along the line of the Bristol to Exeter line and the M5 motorway east of Tiverton and Exeter. It is a part of the Tees-Exe line broadly dividing Britain into a southeastern lowland zone typified by gently dipping sedimentary rocks and a northwestern upland zone typified by igneous rocks and folded sedimentary and metamorphic rocks.

• Standing stone, orthostat, or lith
• Large man-made upright stone, typically dating from the European middle Bronze Age.
• Menhirs’ size can vary considerably, but often taper toward the top..