IT'S time to delve into the Wales history files again! The second series of Hidden Histories, which has been nominated for a BAFTA Cymru award, is now transmitted on BBC Four. The series follows the everyday investigative work of the Aberystwyth-based Royal Commission on the Ancient and Historical Monuments of Wales and the fourth episode which reveals world war one secrets in the Pembrokeshire cliffs will be shown on BBC Four at 7.30 pm on Tuesday, February 16.

With commentary again by Huw Edwards, episode three sees the Royal Commission's Toby Driver flying into the past, on a mission to photograph strange shapes in the Pembrokeshire landscape. The strange shapes are key elements in military operation where nearly 100 years ago, young British soldiers trained here before leaving for the Western Front.

The Royal Commission's military expert Medwyn Parry finds out more about the army training camp at Penally which has been there since 1873.

Also featured in the programme is a house near Raglan, Monmouthshire, that's nearly 500 years old. What's been discovered on re- opening the house is a treasure trove of architectural details, from the 15th century onwards, including medieval wall paintings and a good luck charm from the 19th century. And with plans to open a visitor centre on Parys Mountain, Anglesey, the Royal Commission is helping to put the largest copper mine in the world during the last half of the 18th century, back on the map!

Dr. Peter Wakelin, secretary of the Royal Commission, added: "Hidden Histories is a fantastic series and we're delighted that it's been nominated for a Bafta Cymru award and recognised for the fascinating investigative work being done by the Royal Commission and its partners. The response to the second series in Wales shows how much interest there is in the wonderful heritage of our nation. I hope, with this transmission throughout the UK on BBC Four, that a wider audience will be able to appreciate the amazing history which exists all around us."