There are four important Neolithic burial sites in the Vale of Glamorgan proper of which by far the most important is the Tinkinswood Burial Cairn. A description of this Cairn can be found by clicking on the link below. The other sites are (from west to east) at Laleston, Coity, and St Lythans.

None of these sites appear to be positioned randomly but are located with reference to fixed geographical features. Thus Laleston, Coity and Tinkinswood are all exactly 3,000 poles (approximately 15 kilometres) from the mouth of the Col-Hugh river near Llantwit Major.

We know that Llantwit Major was once a great sacred centre of learning and culture but we do not know why the river mouth should be a geographical reference point. St Lythans lies outside this arc but is located 2,000 poles from Lavernock point, (after allowing for the effects of 6,000 years of coastal erosion).

The burial chambers at Laleston and Coity have collapsed. At Laleston the burial mound is still visible and more or less intact, but at Coity only the stones are left. Both chambers are considerable smaller than Tinkinswood.

Three other ancient burial sites that lie outside the narrow boundaries of the Vale of Glamorgan also appear to be located 3,000 poles from river mouths. Thus a site near Creigiau (map reference ST 077823) and a site near Newport (map reference ST 277851), are both 3,000 poles from the mouth of the Taff (map reference ST193725); while the Burial Mound to the east of Caerphilly (map reference ST 175879) is 3,000 poles from the mouth of the Usk (map reference ST 318830).*

A second common feature that appears to be shared by all sites is that close to each lies another site and a line drawn through the two sites aligns with a distant hill top. In the case of the four sites listed in the first paragraph, the secondary sites are today occupied by the churches at, respectively, Laleston, Coity, St Nicholas and Wenvoe.

*This point is also one of the ends of the ‘Rivers’ line on which Tinkinswood is located