The Ebbsfleet Valley in north-west Kent is just 2.5 km long, with Springhead at its head and Northfleet near its confluence with the Thames. The valley contains nationally important sites of several periods and construction of the Channel Tunnel Rail Link provided a unique opportunity to undertake large-scale investigations. Late Iron Age activity concentrated on the springs at the head of the valley. A Roman "small town" or roadside settlement at Springhead (Vagniacis) developed into an almost unique religious centre within Roman Britain, probably attracting pilgrims from throughout the Empire. In addition to temples, a major mid-2nd century AD sanctuary complex has been discovered, focused on the springs. At its centre was a temple with at least two other buildings and a ritual shaft. Large numbers of coins and brooches, possibly representing offerings, were recovered from the river bed while miniature bronze body parts, representing the location of ailments that required curing, suggest that Springhead was an important healing centre. Another temple, close to Watling Street may have remained in use until the late 4th or early 5th centuries. Three small cemeteries were recorded in addition to the major Pepper Hill cemetery, containing almost 600 burials. There were only limited remains of late Saxon, medieval, and post-medieval settlement in the Ebbsfleet Valley. In the middle of the 19th century Springhead was the site of the earliest commercially grown watercress in the country and pleasure gardens were developed on either side of the river.