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Wednesday 22 Oct 2025

From steam to sustainability: how Taff’s Well continues to connect Wales’ transport past and future

Region & Route:

Wales & Western: Wales & Borders

Fifty years after the Walnut Tree Viaduct was dismantled, its legacy lives on in the Taff Trail just outside Cardiff - where history, sustainability and community now travel side by side. 

 

Welcome to the latest in our series of heritage articles looking at buildings and structures across the Wales and Borders railway in celebration of 200 years of the modern railway. 

Heritage can mean more than preservation and restoration. At times, it’s more about remembering what came before, and making use of some of the remnants of the past today. A fine example of this exists close to Wales’ only natural hot spring. 

The village of Taff’s Well sits just north of Cardiff, nestled in the narrow Taff Valley between the steep slopes of the Garth Mountain and Craig yr Allt. As well as being home to the spring, whose warm mineral waters have attracted visitors for centuries for their supposed therapeutic properties, the village also hosts a striking, slender brick monolith of a chimney. It stands proud, and somewhat out of place, beside the busy A470 dual carriageway. The faint lettering still visible on its side might mislead passers-by into thinking it is a modern folly, perhaps erected in 1977 to commemorate the Silver Jubilee of Queen Elizabeth II. 

In truth, it is neither chimney nor folly, and its story stretches back far beyond the 20th century’s royal celebrations.

Turn of the century 

For over 80 years, the imposing Walnut Tree Viaduct dominated the skyline over Taff’s Well, carrying heavy freight and passenger trains across the river. Built by the Barry Railway Company in the 1890s, it was originally designed to carry coal and iron from the busy South Wales Valleys to the newly established Barry Docks - a port created to ease pressure on Cardiff’s overcrowded Bute Docks. Its rural name contracts sharply with the industrial might the viaduct represented, and comes from a nearby farm and inn, which were well known coaching stops long before the railways arrived.  

Completed in 1901, the viaduct was an imposing sight. The design featured steel lattice girders resting on tall masonry piers, the longest span stretching 300 feet. At over 1,200 feet in total length and rising 120 feet above the river, it was visible for miles around, the rhythmic clatter of steam locomotives part of daily life for the villagers living in its shadow. It took three years and around seven million bricks to complete, and alongside the impressive seven girders, it earned the reputation as one of the finest railway spans in Britain. 

Walnut Tree viaduct retained its strategic importance to the national rail system for decades. The line it carried remained a vital artery until the 1960s, but then the shifting tides of industry and the Beeching-era cuts reshaped the rail map of South Wales. The need for the viaduct dwindled, and between 1969 to 1974, piece by piece, entirely by hand (owing to the congested valley bottom below), it was dismantled. Today, only two of its towering stone piers remain – monuments to the viaduct’s former glories. One is mainly hidden by trees, while the other remains prominent and is adorned with well-wishes for the previous monarch. 

Back to today 

You may think the loss of the line and the remnants of the viaduct are the end of this story.  

However, the line’s former path through the landscape continues to be used, not by rail enthusiasts, but by walkers, joggers, cyclists, and more. This is because much of the former railway alignment is now part of the stunning Taff Trail, a 55-mile traffic-free corridor from Cardiff Bay to Brecon that follows the track laid down at the height of the steam era. 

In this way, the Walnut Tree Viaduct’s role as a transport link continues, albeit in a greener, quieter form. Its transformation mirrors a broader shift across the UK, where disused railways are being reimagined as sustainable travel and tourism routes, preserving history while serving present-day needs. 

And what about tomorrow? 

Taff’s Well remains an important point on Wales’ active rail network. The main Cardiff-to-Merthyr line still runs through the village, and Taff’s Well station is a busy commuter stop. Network Rail and Transport for Wales are investing heavily as part of the South Wales Metro project, with a new depot, modernised station facilities, and improved services planned. 

While the Walnut Tree Viaduct is gone, its legacy endures in the towering stone piers that frame the valley, and in the trail that follows its course. Steel, stone and sustainability bind the past, present, and future of this village together, and long may that continue.