The major Roman fort complex was spotted on parched grassland near Brecon, Powys, and the marching camp near Caerwent in Monmouthshire.

Aerial archaeologist Toby Driver said he could not believe his eyes when he spotted the fort from the air.

He targeted reconnaissance flights in a light aircraft to where the drought conditions were most severe across the length and breadth of Wales.

When crop marks show in drought conditions Dr Driver said the Royal Commission's aerial survey only has a few weeks to record the sites before rain or harvest removes them.

The Roman fort complex discovery near Brecon was a "rare discovery for Wales" and was made following a tip from Dr Jeffrey Davies, who he has been working with on another project - the Abermagwr Roman villa excavations near Aberystwyth.

"Jeffrey Davies noticed an anomaly in Roman coin finds near Brecon, reported under the Portable Antiquities Scheme (PAS)," explained the aerial archaeologist.

"He had a hunch that the coins, of the Emperor Claudius, could indicate a lost early Roman fort, and passed a grid reference to me the day before a flight into central Wales.

"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."

The Royal Commission will now begin cataloguing and mapping the discoveries to make the information more widely available online.

To read the complete article, see:Hot summer unearths Roman discoveries in Wale(www.bbc.co.uk/news/uk-wales-23628630)