Durrington Walls, overlooking the River Avon near Amesbury, is the largest known Neolithic henge in the United Kingdom.
Notes on verification
Confirmed by Wikipedia, Discovering Britain, and archaeology/tourism blogs; minor nuance exists regarding 'largest henge' vs 'second-largest palisaded enclosure', but the core claim is well supported.
Sources
- Prehistoric Age Browse - Page 1 (britannica.com)
- https://www.discoveringbritain.org/activities/south-west-england/trails/durrington-walls/ (discoveringbritain.org)
- https://blog.histouries.co.uk/2017/05/23/durrington-walls-the-largest-henge-monument-in-britain/ (blog.histouries.co.uk)