Urban Trawl: The Valleys

'South Wales needs a Plan!' declared a book published during the Great Depression, on one of the 'distressed areas' hit hardest during the 1930s. The cities of South Wales – Cardiff, Newport, Swansea – became boomtowns in the late nineteenth century for one reason, and one reason only – to export and process the produce of the coal seam that ran across the valleys, and the tiny industrial towns that arose to service them. Now, in 2011, it seems the place needs a Plan, again; among the places worst hit by the recession are the likes of Merthyr Tydfil, which face huge rates of unemployment. The same places hit, in the same ways, yet again. Iain Duncan Smith helpfully suggested that the people of Merthyr up sticks to Cardiff, where there are nine unemployed people for every job vacancy. The Valleys are at least topical.

Does it even make sense to include the Valleys in something called 'Urban Trawl'? They don't fit the pattern of any other rural or urban settlement in the UK. These long rows of terraces, distributed along steep, scarred and verdant hills, are obviously too dense and industrial to be 'the countryside', no matter how gorgeously they might nestle in those undulations; they're largely too small, too bounded to feel like towns as commonly understood. They could be considered one great big town, parted by billowing topography. You'd be either a fool or very poor to attempt to negotiate it without a car. Linking the Valleys together coherently could only work via expensive, dramatic solutions – an underground railway, a system of funiculars. The place does get some investment. Since the mines were crushed in the 1980s, with the steelworks gradually following suit, call centres and local government offices filled the gap; talk of remaking them into Silicon Valleys came to little. The Valleys are often so beautiful that you could imagine them one day becoming tourist centres, but snobbery checks that. High architecture, especially of the twentieth century, has touched them little, although there are remarkable finds to be had.

We begin at Aberfan, whose tightly packed terraces packed up along hillsides introduce the scene – an urban-rural landscape mirrored in the linear strip of gravestones to commemorate the children killed by a landslide of coalfield waste in 1966. An early reminder not to romanticise that industrial past. From there, we travel to Merthyr Tydfil, another place full of meanings and resonances. The red flag, as a political symbol, was born here, in the Merthyr rising of 1831. It would have been nice for this have been commemorated in the public art that is invariably scattered around a post-industrial town, but there is at least a very appropriate welded metal sculpture by Charles Sansbury marking the entrance to the town, placed on a roundabout. Brackish, severe, beautiful in its harshness, it is very Merthyr. Next to the roundabout are offices for the Welsh Assembly (a nothing building), and the town's only tower block. Nondescript as architecture, it's notable both for being one of the more urbe-in-rus towers in the UK, and for commanding one of the finest views conceivable, for what is no doubt a knock-down price. The poverty of the town fairly whacks you in the face, especially in the dense concrete shopping precinct of St Tydfil, but it looks like its residents care for their area more than is common in the south-east of England. The terraces are spick, span and colourfully painted, rising up the slopes in a manner that almost evokes Brighton. What you can't miss is the desuetude of the public buildings. The Miners Institute is without roof, overtaken by greenery. At the town's centre is a gigantic Tesco, which from a hill looks exactly like the steelworks supermarkets replace. At the town's other exit is the recently closed streamline moderne Hoover Factory. Merthyr Tydfil also has a signposted 'Café Quarter'.

The next village we stop in is Mountain Ash, in the Cynon Valley. Rows of precise, clipped council terraces lead towards one of the Valleys' several breath-stealing panoramic views, where the terraces, the hillsides and the variously derelict chapels and institutes come together in an accidental composition. The fulsome baroque town hall points out that it serves an 'urban district council', which answers the question posed in our introduction, although Mountain Ash's population is just over 7000. That said, it has bustling traffic at rush hour, presumably as it commutes back from Cardiff and Newport. A barn houses the local Citizens Advice Bureau. The landscape is magnificent, with forests of pine (apparently the result of post-war planning decisions) tightly enclosing what, for once, can aptly be called an urban village. The hills make the place glorious as spectacle, and perhaps horribly claustrophobic as a place to live.

That certainly seems the case with Brynmawr, another series of terrace strips which once abutted the famous Rubber Factory, surely for a time Wales' most famous 20th century building; a failed attempt at co-operative industry, at doing things differently, eventually demolished in 2001 in defiance of listing. By the end, it was a Semtex factory. After a few hours in the traumatic townscape of Ebbw Vale, you could easily imagine terrorist cells emerging, avenging the damage done to the town and its people. The anti-tank measures and frisking at Cardiff's Senedd suddenly make sense. Follow the sign to the DHSS, and you can find some of the saddest sights in Britain. Worn, never-changed signs to the Civic Centre lead to a decent, if undemonstrative 1960s complex, its office blocks surrounded by the churned-up paving of a car park. A distressed leisure centre has a growth on it, the bright yellow and green tentacles of swimming pool flumes, with broken glass underneath. An angular underpass from here brings you to the rest of the town, and it has the most eloquent graffiti I've ever seen. 'AMAZING VALUE £5 – A WORKING CLASS HERO'. Then there's a small recreational ground, and the start of the terraces. The street lights are on. It's three o'clock in the afternoon, in July.

There's a lot to love in Ebbw Vale; the incongruously enormous, hulking scraping spire of Christ Church, dwarfing the terraces, evidently intended to be a landmark for miles around; the compact centre, with the unexpected pleasure of a Festival of Britain interior in the Crossing Café; another sadly derelict austere-baroque Workers' Institute; even the concrete car park at its centre, a fittingly muscular design reminiscent of Gateshead's demolished Trinity Centre. This one was saved, but improved by being painted white and covered in metal wire. The public art here, sadly in contrast to Merthyr, is pro forma, a swooping metal clock surrounded by steel balls. It was commissioned the year after the steelworks closed; the site is still being cleared for impending 'regeneration'. These things always feel like a sop, but the rest of the country owes Ebbw Vale and neighbouring Tredegar a favour, to put it mildly.

On a hilltop between the two towns, commanding views of only partly re-landscaped industrial waste, surrounding works, terraces and hills that would be crammed with sightseers were they elsewhere, is a memorial to NHS founder Aneurin Bevan. It's the most striking tectonic thing in the area, although it goes back to the very foundations of architecture. It is a stone circle, in the place where he used to speak to constituents. It feels moving, mystical, an ancient monument to the belief in a viable future. We were there on the NHS' 63rd birthday.

Tredegar has one of the Valleys' nearest things to a town plan – an iron column with a clock on top, around which the centre revolves. Here is 'Spirit of Bevan', a film co-operative. The local miners' self-run health service was the NHS' original inspiration. There's a little monument also to a more modernist social architecture – Powell Alport and Partners' Tredegar Library, a striking, dynamic little piece of Brutalism, a riot of angles and geometries now accompanied by a mural of the town's radical heritage. It bears repeating that the idea of the National Health Service was born here, not in Manchester, not in Birmingham, not in London. And as in the surrounding towns, what the rest of the country has to present this place is out-of-town retail parks and call centres.

The last thirty years has fairly clearly had little to offer the Valleys. The finest piece of new architecture we see, by a long chalk, is Arup's Chartist Bridge, in Blackwood. Opened in 2005, it's a sweeping cable-stayed bridge, simple and dramatic enough to shame all our Calatrava imitations. It's encouraging that this monument's function is to bring these scattered towns closer together, irrespective of the exurban dross of the 'Sirhowy Enterprise Way' nearby. Next to it is a colossal socialist realist sculpture of a Chartist, by Sebastian Boyesen. Constructed from steel mesh, it looks ghostly, an apparition of a power that has disappeared, for the moment.