A 300 million-year-old fossilised forest, discovered at a Victorian steelworks, is set to open to the public for free as part of a Wales-wide open doors festival.

Located in Brymbo, Wrexham, the unique archaeological site was uncovered by accident in 2003 amid the clearing of the former steelworks which closed in 1990.

A heritage project made up of volunteers and students has since found fossils just metres away from the steelworks, dating back to Paleozoic Era, some 200 million years before the dinosaurs.

More than 20 “towering” fossilized trees have also been found with “their root networks still intact” and organisers now hope the site opening in September will help recruit more volunteers.

Nicola Eaton Sawford, chief executive of Stori Brymbo, said the group were “constantly finding things” and certain elements could not be identified because they are being found for the first time.

“The students are taking them away to the universities and we’re sending photographs and consulting people and bringing people in to work out what it is we’ve found,” said Ms Sawford.

Someone whose Brymbo history dates back generations is Nic Jones, one of the volunteers on the dig.

Mr Jones said his great-great-grandfather, Tom Jones, worked as a furnace man in the iron works and it gave him “goose pimples” to work on the same site as him.

The site received £10m in funding in 2024 to construct a visitor centre with both a focus on its industrial history and the discovery of the fossilised forest.

The forest received national recognition to protect its future in 2015, by being made a Site of Special Scientific Interest.

Despite the site stopping producing steel 35 years ago, volunteers said it was still producing surprises, with remnants of “giant” millipedes and dragonfly wings among some of their recent finds.

Work to restore the site, which was previously open to the elements, began 12 months ago, but “delicate palaeontology work” can now continue in all weathers as the area has been enclosed in a shelter.

Entry will be free to all visitors from 7 September, as a part of Cadw’s open doors month.

There are hopes the factory will eventually operate as a main hub of the project, selling local produce and interpreting its long history.

Gwilym Hughes, chief executive of Cadw described the project as a”festival of heritage” which brings history “right into the heart of communities” for everybody, young people and older people alike.