Cloaked by time's leafy shroud, the prehistoric settlement of Gaer Fawr lies all but invisible beneath a forest in the lush Welsh countryside. Now the 2,900-year-old structure lives again, thanks to a digital recreation following a painstaking survey by the Royal Commission on the Ancient and Historical Monuments of Wales.
    "Because Gaer Fawr is densely wooded, it's been little understood in the past," said Royal Commission archaeologist Toby Driver. The study involved thousands of measurements taken in 2007, which were used build a digital terrain model of the 21-acre (5.8-hectare) site. "The thought behind the survey was that if we could map the contours underneath the woods, we could then strip the trees off and then see what the fort looked like in the landscape," Driver said. The results show the oval-shaped stronghold was defended by five tiers of stone-faced earthen ramparts, each measuring up to 26 feet (8 meters) in height. Two entranceways led up to gates to the northeast and southwest of the summit, where a timber fortress once stood. The hill fort's flat summit was later extended to the west, possibly to accommodate a growing population.
     "It's not a single build," Driver said. "New ramparts and new gateways were constructed over earlier ones." Past archaeological finds, including a nearby cache of Bronze Age weapons, suggest the hill fort was active from about 900 BCE until the Roman invasion of Britain in 43 CE. The study team says the fort occupied a strategically important area for trade and agriculture between the fertile plains of England and the Welsh hills. The border region has the highest concentration of Iron Age hill forts in Western Europe, Driver noted. "This land would have supported a lot of people and hill forts would have risen up to control these populations," he said.
     Phil Bennett is archaeological manager of one of the few extensively excavated Iron Age forts in Britain: Castell Henllys in southwestern Wales. Larger hill forts such as Gaer Fawr commanded the surrounding landscape not just visually, but in terms of natural resources, Bennett said. Huge amounts of timber would have been required both for building the fort palisades—strong defensive fences—and the dwellings people lived in, he said. Roundhouses—circular buildings used as living quarters—excavated at Castell Henllys, for example, are estimated to have required some 30 oak trees, 80 to 100 hazel bushes, and 2,000 bundles of reeds, Bennett said. "We think these hill forts owed as much to elites showing off their status and power as any real need for defense," he added.
     The terraced ramparts wouldn't have held an enemy at bay for long, according Bennett. "Probably what was going on in the Iron Age was raiding rather than sieges and open warfare," Bennett said. "They would have taken things like cattle and people as slaves." An angular bank dividing the interior of the fort is so different from the site's other earthworks that researchers suspect it dates to early medieval times. "The fort has these prehistoric curving ramparts, but when you get to the top there's this big, straight bank which is very unprehistoric," the study team's Driver said. After the Roman period, Welsh princes rose to prominence in the region, he added. "It may be that Gaer Fawr, in common with other hilltops in central Wales, was occupied by the court or castle of one of these early Welsh princes," Driver said.

Source: National Geographic News (21 November 2008)