Members of the public helped to seal the panel’s decision after being given a chance to vote as part of The European Heritage Awards/Europa Nostra Awards, which recognises exemplary achievements in the field.
The major conservation project was launched to secure the bridge’s future resulting in the structure being put under wraps for almost two years with limited access to visitors while the work was being carried out.
The renovation was completed last spring allowing tourists to come flocking back to the attraction in numbers. Among the highlights of the revamp was a change in colour to its original red-brown along with repairs to cracks and stresses in the historic cast ironwork.
English Heritage chief executive Kate Mavor said: “The care of internationally-significant structures such as the Iron Bridge is central to English Heritage’s charitable purpose, and we are delighted that our conservation project has been recognised with such a prestigious international award.
“Since its construction as the first single span cast iron bridge in the world, the Iron Bridge has attracted admirers from across Europe and the world.
"It is especially pleasing, therefore, that the work our charity has undertaken to protect it for future generations has now received its own international recognition.”
When it was finished in 1779, the Iron Bridge was the first single-span arch bridge in the world to be made of cast iron and was a turning point in British engineering. It now sits at the heart of a UNESCO World Heritage Site and has been in the care of English Heritage for 45 years.
The trust completed the conservation of the bridge in 2019 and the task featured more than100 specialist repairs to the historic ironwork and 300 bespoke iron wedges cast to hold the deck in place.
The bridge was repainted in its original red-brown colour after this was revealed following historic paint analysis.
Urgent restoration was launched after investigations showed that it was under threat from cracking due to stresses in the ironwork dating from the original construction, ground movement over the centuries, and an earthquake in the 19th century.
Specialists set to work in late 2017 to ensure that the entire structure was cleaned, conserved and repaired, from the iron radials and braces holding the bridge together to the deck plates and wedges, as well as the main iron arch.
The bridge was announced as one of the winners earlier this year by a judging panel of experts, however, members of the public were also given a final say in an online vote.
Yr Ysgwrn, Trawsfynydd, Snowdonia, was also a conservation project winner.