Pair of British amateur archaeologists believe they have found the hidden source of a Roman aqueduct 1,900 years after it was inaugurated by the Emperor Trajan. The underground spring lies behind a concealed door beneath an abandoned 13th century church on the shores of Lake Bracciano, 35 miles north of Rome. Exploration of the site has shown that water percolating through volcanic bedrock was collected in underground grottoes and chambers and fed into a subterranean aqueduct, the Aqua Traiana, which took it all the way to the imperial capital. Prof. Lorenzo Quilici in the Aqua Traiana Centuries later, it provided...