BBC News

Heatwave unveils ancient settlements in Wales

Published
Related Topics
  • UK heatwaves
image copyrightRCAHMW
image captionThe Iron Age hillfort of Gaer Fawr near Lledrod, Ceredigion, looking across the parched landscape

Ancient hillforts and Roman settlements have been revealed by the heatwave.

The dry spell has left parched fields with unmistakable "crop marks" painted into the landscape.

The Royal Commission on the Ancient and Historical Monuments of Wales (RCAHMW) has been busy recording the details - before they disappear when it next rains.

Sites across Wales have been captured from the air.

  • Phew - what a scorcher - 1976
  • Hot tots: How are parents coping with the heat?
  • Too hot for trousers
  • A fishy tale as rivers run dry

The crop marks are made by vegetation drawing on better nutrients and water supplies trapped in long-gone fortification ditches - leading to lush green growth that stands out.

HOW IT WORKS:

image copyrightRCAHMW
image captionAncient settlements are scattered across Wales - such as Iron Age hillforts and Roman fortifications

Most ancient settlements added fortification or drainage ditches around them.

image copyrightRCAHMW
image captionOver the centuries, the settlements disappear and farming takes place

When the settlements disappeared, those ditches became filled in - but it also meant that soil was deeper in those areas.

image copyrightRCAHMW
image captionWhen the land dries out in the prolonged heat, the old fortifications retain moisture, so crops are more visible

Deeper top soil sections covering the old settlement ditches means those areas hold onto more water and nutrients during intense dry spells - and crops are very quick to take advantage of it - growing thicker, taller, and greener.

It is easy to spot from the air:

image copyrightRCAHMW
image captionThe almost ploughed-down medieval castle mound at Castell Llwyn Gwinau in Tregaron, Ceredigion, showing clearly under parched conditions
image copyrightRCAHMW
image captionThe buried ramparts of Cross Oak Hillfort, Talybont-on-Usk, showing as crop marks in Powys.
image copyrightRCAHMW
image captionExtensive crop marks of Trewen Roman farmstead or villa, Caerwent, Monmouthshire
image copyrightRCAHMW
image captionA newly discovered Roman fortlet near Magor, Monmouthshire, emerging in ripening crops
image copyrightRCAHMW
image captionNewly discovered crop marks of a prehistoric or Roman farm near Langstone, Newport

Related Topics

More on this story

  • Wildfires putting 'tremendous pressure' on firefighters