Divers surprised by iron age port Maev Kennedy, arts and heritage correspondent Tuesday September 17, 2002 The Guardian Archaeologists diving deep beneath the ferries and yachts criss-crossing Poole harbour have found startling evidence of the oldest working harbour in Britain, built centuries before the Roman invasion. Timber pilings excavated from a deep layer of silt on the sea bed have been radio-carbon dated at 250BC, the oldest substantial port structures by several centuries anywhere on the British coast. They suggest an iron age trading complex, with massive stone and timber jetties reaching out into the deep water channel, providing berths...