The triple henge complex at Thornborough is a relatively unknown place, yet it comes with a pedigree that invites many superlatives.

The Site

Thornborough is a religious site that is 5,000 years old; it comprises the world's only triple henge complex. This is a single precinct that was built as part of a religious pilgrimage point. The henges are circular ditches - three 'circus rings', each 240m in diameter - with external earth walls that serve to create the UK's largest ritual complex of the period.

The henges themselves are the largest truly circular ones in Britain. Their design is so exact that up until the 1930s they were regarded by many archaeologists as being of Roman construction.

The Henges and Orion

They also have other aspects of interest. They may well have a relationship with the constellation Orion - being a more accurate reflection of Orion's belt than the Great Pyramids of Giza. If so, Thornborough is the world's earliest Orion complex, predating the pyramids by 1,000 years.

There are a number of possible Orion alignments within the monuments. The first is the most obvious: the three henges themselves are in an identical alignment to Orion's Belt. However, this could of course be by pure chance.

The earliest Orion alignment comes from the Cursus monument that is now largely quarried out and underlies the central henge. Cursus monuments are amongst the earliest ritual monuments in Britain and are thought to be ceremonial causeways. If you imagine a very wide and straight Roman road - with banks and ditches on either side - this is similar to how the Cursus would have looked.

The Cursus is aligned roughly east-west and it is to the west that the Cursus is thought to have aligned with the setting of Orion in 3,500 BC. The eastern alignment may well have been set to the midsummer solstice sunrise, for although the monument was built using straight lines, at its centre (the point under the central henge) it changes direction slightly: an adjustment for its eastern alignment - possibly the sunrise?

The Cursus was originally at least 1.2 miles in length and may well have been much longer, since it disappears under the village of Thornborough. It is this Cursus that may have been the first monument in the world aligned to Orion.

A further relationship with Orion was suggested by academics at Newcastle University. This is based on the alignment of the henge entrances, of which there are two for each one: they are on opposite sides of the henges' perimeter, forming an alignment roughly north-south. It appears that when viewed from the centre of the henge, the southern entrance frames the zenith of Orion at the time when Sirius is rising to the east.

Where are the Henges?

The Thornborough Henges are located in rural North Yorkshire, close to the picturesque market town of Masham. Tarmac Northern, the company that is quarrying the area, owns much of the site. Currently they do not allow visitors. However, the central henge is very close to the road between the villages of Thornborough and West Tanfield and can be inspected easily from the verge.

Other Related Websites

• The 'Friends of Thornborough' is a voluntary campaign group dedicated to preventing further damage to the landscape setting of the Thornborough Henge complex.