Heatwave reveals lost archaeological sites across Wales

Heatwave reveals lost archaeological sites across WalesImage source, RCAHMWImage caption, New details have been collected of buried Roman buildings at Caerhun Roman fort in ConwyByAngharad ThomasBBC WalesPublished48 minutes agoLost archaeological sites have emerged in grasslands across Wales after a prolonged spell of hot and dry weather. Wales has seen about 5% of the average rainfall for July, after a series of back-to-back heatwaves and a drier than usual April to June. A drought has also been triggered in parts of Wales. Experts said these dry conditions have brought to light a range of hidden archaeological remains, including Roman buildings and practice trenches from World War One.Many are only visible from the air as distinctive marks in crops and grass, with some not being seen for "two or three decades", according to the Royal Commission on the Ancient and Historical Monuments of Wales (RCAHMW).Image source, RCAHMWImage caption, Parchmarks of World War One practice trenches are seen beneath a golf course in Deganwy, ConwyThe crop marks are made by vegetation drawing on better nutrients and water supplies trapped in long-gone fortification ditches - leading to green growth that stands out.But they can disappear as quickly as they emerge once the weather conditions change.Archaeologist Dr Toby Driver has been racing against the heat to record and study the monuments. He said they would normally have to wait every five to seven years for "a record heatwave summer for aerial archaeology", but now they come "every year". Image source, RCAHMWImage caption, A previously unrecorded Iron Age or Romano-British double-ditched farmstead was revealed in ripening cropmarks near Llandysul, CeredigionRCAHMW said the east and north-east of Wales has been very dry since mid-May, while much of west and south Wales stayed fairly damp and green.However, the series of heatwaves in late June scorched off grasslands across Wales.It revealed "monu...