BRECON, WALES—Thanks to an unusually hot summer in Wales, aerial survey of parched grassland has revealed dozens of previously undiscovered sites. Archaeologist Toby Driver of the Royal Commission on the Ancient and Historical Monuments of Wales studied a number of crop markings in parts of the country that have been hardest hit by the drought conditions and found a number of Iron Age farms and forts, as well as an important Roman defensive structure near the town of Brecon. "I couldn't believe my eyes when the pilot and I approached the location and saw fading crop marks of a major Roman fort complex, lost beneath fields and a road for nearly 2,000 years," says Driver. One of the starkest discoveries was the outline of a previously unknown medieval church in northern Wales.