The sweltering summer heatwave that has gripped Britain and Ireland is also uncovering some of the islands’ ancient history.

One of the greatest finds is being described as a “new Stonehenge”, a 5000-year-old ring of stones in Ireland’s County Meath that is thought to be a neolithic tomb.

The henge is the latest find among seven monuments within a couple of kilometres of each other in a UNESCO World Heritage site in the Boyne Valley.

Also nearby is Newgrange, another 5000-year-old tomb. Stephen Davis, an assistant professor in archaeology at University College Dublin, told the BBC he thought the area had the densest concentration of such monuments anywhere in the world.

Author and self-described “ancient mysteries explorer” Anthony Murphy and prehistoric archaeology explorer and blogger Ken Williams captured pictures of the “new” henge with a drone.

Heatwave reveals hidden ancient monuments near Newgrange in County Meath. Grass grows greener over the ruins due to moisture levels. Found by @mythicalireland and @shadowsandstone. pic.twitter.com/Yv8rNRT8Wx

— Barra Best (@barrabest) July 11, 2018

Mr Murphy told the BBC he “giggled with excitement, expecting someone to pinch and wake me up” when he noticed the “amazing detail” in the photos.

“We knew straight away. This had never been seen or recorded before,” he told NPR.com.

Mr Murphy and Mr Williams sent their pictures to archaeologists, who confirmed their suspicions: They had found the footprint of an ancient henge, or enclosure.

The growing use of drones in aerial photography is proving a boon for those who hunt out ancient and prehistoric remnants of early life in the British Isles.

Any signs of such long-forgotten buildings and earthworks are usually hidden by grasses or crops. Marks in the ground are revealed only when vegetation on top of wood or stone grows or dies at different rates to surrounding material because of the hot weather.

Other finds across the United Kingdom and Ireland this northern summer include Roman villages in Wales and Norfolk, and the outline of a Victorian garden at Gawthorpe Hall in Lancashire (above).

At Gawthorpe Hall, museum manager Rachel Pollitt said the “ghost garden” appeared most summers, but was quite spectacular this year.

She said the dry weather had shown up “other things … on the sides that we haven’t seen before, possibly from previous gardens”.

In Hampshire and Cambridge, meanwhile, photographers have found the outlines of World War II airfields and shelters. Elsewhere, “drowned villages” are about to be revealed as reservoirs empty due to the long dry spell.