What is a henge?

What a henge is

The ditch inside the bank is the reverse of a defensive arrangement, which separates henges from hillforts and other defended enclosures. Historic England's scheduling texts describe henges as enclosing a level area more than 20 metres across and record about 80 in England. Smaller circular enclosures of similar form are called hengiform monuments, while the largest henges, such as Avebury and Durrington Walls in Wiltshire, enclose areas several hundred metres across. Many henges have been levelled by ploughing and are known only from cropmarks on aerial photographs.

How henges look on LiDAR

A surviving henge shows as a ring of bank with a ditch inside it and a level interior, broken by one or two entrance gaps. Sky-view factor shows the internal ditch as a dark ring, so the ditch-inside-bank arrangement is easy to confirm, and a local relief model shows heavily ploughed examples that survive only a few tens of centimetres high. Stones and timber settings inside a henge are usually not visible, because stones are small or removed by filtering and timber circles survive only as buried post-holes.

See LiDAR visualisations explained for what each method shows.

What can look like one

Disc barrows also have a bank outside a ditch but are much smaller and have a small central mound, and ring cairns, animal pounds, circular tree-planting banks and dew ponds can form similar rings. Hillforts and most other enclosures have the ditch outside the bank.

Protection

Historic England considers all henges to be nationally important, and many are scheduled monuments protected in England by the Ancient Monuments and Archaeological Areas Act 1979 and in Wales by the Historic Environment (Wales) Act 2023.

Examples on the LiDAR

Where they are

Counties with the most henges that have a page here.

More examples