Dudley's 428-million-year history to feature on Portillo's TV show tonight

The limestone caverns of Dudley's Wren's Nest National Nature Reserve will take centre stage in tonight's edition of Michael Portillo's Great British Railway Journeys.

It follows episodes this week which have taken in Shrewsbury, Telford, Ironbridge and Wolverhampton. Tomorrow's episode will see him travel from Birmingham to Wednesbury, where he will visit the headquarters of the West Midlands Metro tram network.

The former cabinet minister turned TV presenter also boards a barge through the Dudley Canal Tunnel and explores racial tensions in Smethwick which led to a visit from American civil rights campaigner Malcolm X during the episode of the programme.

It sees Graham Worton, keeper of geology at Dudley Council tells the story of how a prehistoric seabed laid the foundations for the Industrial Revolution at Wren's Nest. 

He explains how the beauty spot, now famed for the Dudley Bug trilobite fossil and part of the Unesco Geopark, was once south of the Equator, before a shift in the tectonic plates planted it firmly in the north.

Mr Worton tells the presenter how Wren's Nest is one the most remarkable geological sites on the planet.

"Contained within these rock layers are some of the most beautiful, spectacularly preserved fossil animals in the whole world," he tells him. Volunteers Paul Floyd and Rob Broadbent from the Friends of Wren's Nest also talk about the historic importance of the site.

In the programme, Mr Portillo learns from Kate Langley of Dudley Canal Trust how in 1775 the second Viscount Dudley spotted an opportunity to exploit the vast mineral resources of his land by digging a tunnel to connect Wren's Nest to the national canal network.

"Dudley became one of the early industrial centres for iron," she tells him. "At the height of Dudley Tunnel, there were a hundred boats coming through every day."

The programme will go out weeks after Dudley MP Sonia Kumar challenged culture minister Sir Chris Bryant to support multi-million pound proposals from the canal trust to reopen the tunnels to the Seven Sisters limestone caverns at Wren's Nest.

Miss Kumar told a Westminster Hall debate on tourism that the plan, which would see the vast labyrinth of limestone caverns opened to the public for the first time since 1967, would bring half a million extra visitors to the town during its first eight years. 

A previous scheme to link the Seven Sisters with the Dudley Canal Trust narrowly missed out on £23 million lottery funding in 2007, when it became one of four schemes shortlisted for a vote by television viewers on where the money should go.

Visitors would have travelled underground by boat, and rise to the surface by an inclined lift, with an interpretation centre explaining how 428 million years of geology led to the Black Country becoming the ‘workshop of the world’.

Earlier this week, Mr Portillo visited Shrewsbury where the took part in a battle re-enactment, took a ride on Telford Steam Railway, and learned of the role that Coalbrookdale and Ironbridge played at the dawn of the modern iron-and-steel industry. He also visited Wolverhampton to discover the role the once-sleepy market town played in the birth of modern Britain.

The shows can also be viewed on the BBC's iPlayer service.