The site, North of Heathrow Airport and half a kilometre across, was excavated in advance of gravel extraction over a period of five years, 2010-2014, one phase per year, phase One at the North end, then work moved down in a clockwise direction. Phase 3C contained most of the archaeology, comprising a great number of features. There were 6000 contexts and 10,000 features including over 30 pits – some containing charcoal and human bone - 211 postholes and stakeholes, 190 slots, 5 evesdrip gulleys, 60 wells and waterholes, 500 field ditches, 2 ring ditches, 4 hollows, 256 tree throws, 289 other natural hollows plus a possible dewpond containing Roman pottery.

After stripping off topsoil then subsoil they came down to brickearth and could immediately see archaeological features, mostly ditches, also a feature they called “the splodge”. Bob would mark the edges of features to fix them in relation to the OS National Grid. Small pits and wells were half-sectioned. There was not much Mesolithic: rivers are places where Mesolithic activity tends to be found, and the site was some distance from local rivers – the Colne 2.5 km to the West, the Crane 2 km to the East. In the Neolithic the site would still have been heavily wooded, with clearings with monumental structures.

The Neolithic landscape here would have included many small features including hengiform monuments under 20 metres across, plus a linear monument possibly like the Stanwell Cursus. The most interesting Neolithic feature was a hengiform monument just over 15 metres across, probably used for ritual or funerary functions, with just outside it a number of cremation burials in pits. One-third of its ditch was excavated in segments. Prehistoric specialist Jon Cotton pointed out this monument was close to the much later parish boundary, which also had features called Shasbury Hill and Fern Hill alongside it, perhaps indicating these old features were still visible when it came into being. Out of some of the Neolithic pits came fragments of human and animal bone, plant remains, worked flints including scrapers, blades, an adze and a fabricator, and a transverse arrowhead from a ditch. Postholes were found which may represent structures - about six Neolithic houses have been found near Heathrow, and there may be some at Sipson.

In the Bronze Age a lot of woodland had been cleared away, with the laying out of “Celtic” fields, i.e. coaxial field systems used for pasture and stock rearing - entrances to the fields appeared to be in one corner, which probably indicates livestock - with scattered settlement within the fields. Circa 500BC the field systems were delineated by ditches, some interrupted. Associated with them were waterholes. Local drainage was bad - some of the waterholes filled up with water during the excavation; they were very deep. A Middle Bronze Age loom weight bore a rare “stabbed” decoration. From the Late Bronze Age there were more cremation burials and a very small ring ditch containing fragments of human bone, so perhaps with a funerary function. Some cremation burials might have been buried in a bag rather than a pot.

Yvonne Masson