Archaeological excavations along the route of the A2 Pepperhill to Cobham Widening Scheme, near Gravesend in Kent, uncovered a rich archaeological landscape reaching back 10,000 years. The discoveries include a sensational series of rich burials dating to around the time of the Roman conquest, which are among the finest ever found in Britain. Important evidence for prehistoric and medieval settlement was also found.

The excavations were carried out by OA South for Skanska Construction (UK) Limited on behalf of the Highways Agency along a new road south of the then existing A2 between the Pepperhill and Marling Cross junctions. The road varied from 50 m to 80m wide, and nearly 3km of the route (some 15ha) was stripped to archaeological levels prior to excavation. The route lay immediately north of the line of the previously excavated High Speed 1 (HS1). Additional areas (totalling 0.85ha) were excavated c 1km further east, where new ponds were being created north and south of the A2 alongside the Cobham services.

Features of every period from Neolithic to post-medieval were found, together with residual Mesolithic flintwork. Early Neolithic activity included one very large posthole associated with a flint scatter east of Tollgate. Later Neolithic/early Bronze Age activity was slight, except for a Beaker pit containing a large assemblage of finds just west of Tollgate, not far from a double Beaker burial on the adjacent High Speed 1.

In the later middle Bronze Age two partial enclosures associated with probable metalled trackways were found, one containing a house, pits/hollows and fences, the other without internal features, but becoming a focus for later cremation burials. Scattered pits and cremations were also found further west. Late Bronze Age and earliest Iron Age activity was very sparse, but early Iron Age groups of pits were found at intervals along the route, often with four-post structures and occasionally ditched boundaries. Some of the pits contained very rich assemblages of finds indicative of ritual deposition, and also included the largest collection of briquetage of this period from Kent. In the middle Iron Age activity became nucleated west of Tollgate, where another metalled trackway had enclosures, pits and four-post structures either side. Also in the middle Iron Age a major ditched boundary was dug overlooking the Downs Road dry valley, and burials were made within it and at its end. A ditched settlement was established at Cobham in the late Iron Age, but did not continue into the Roman period.

Most exciting were rich cremation burials of the late Iron Age and early Roman period, probably representing successive generations of a local family, whose rise to prominence between the invasions of Caesar and of Claudius coincides with the growth of the cult centre at Springhead (at the head of the Ebbfleet Valley) nearby. One of the burials included two pottery jars and two cups, six brooches, four of bronze or brass, two of which were joined by a finely-made chain, and two others of iron.  These were in a wooden container. In the other burial, the ashes were contained within a bucket made of staves of yew wood bound with highly polished and decorated bronze strips. There were also two pottery jars and a polished bronze cylinder, possibly part of a metal and antler cup. Equally spectacular was the array of objects that accompanied the human remains within another grave. The assemblage included the remains of a gaming set, a highly-decorated brooch, thirteen pottery vessels, including fine cups and dishes imported from France, and three bronze vessels, comprising a large wine mixing bowl, a jug (ewer) and a pan (patera). All three of the bronze vessels were imports from Italy, and are very similar to examples found at Pompeii.

We wanted as much information as possible from the high-status Roman burials, so a 3-D record was made of the objects in the largest grave while still in the ground by laser scanning. Metal objects were coated with a special wax to prevent them decaying on exposure to the air, and complex objects were lifted in soil blocks for excavation in the laboratory. The blocks were x-rayed to reveal the objects contained within them, before they were carefully excavated.  A special arm connected to a computer was used to create a detailed 3D record of the position of the objects within each block. This was particularly useful for recording the bronze tacks and strips of a table from the first grave, providing valuable information on how this piece of furniture would have looked.

Other burials continued until the later 3rd century AD, when settlement activity also ceased. Fields were laid out alongside the major Iron Age boundary, and middle and late Roman burials continued in and alongside it, one of whom isotope analysis has shown to be a foreigner.

Only a single isolated sunken-featured building could be dated to the Saxon period, but three low-status medieval settlements of the 11th/12th centuries were found, two west of Tollgate and the third east of Cobham services. All three were characterised by sunken-featured buildings. Only one settlement continued and grew, but was abandoned in the mid 14th century.