Where Ironbridge and Pontcysyllte Aqueduct rank on national list of best (and worst) World Heritage Sites

Aiming to help preserve places of "outstanding universal value", Unesco began creating World Heritage Sites in 1978.

Then, just 12 sites were on the list, including the Galápagos Islands and Yellowstone National Park.

Today there are more than 1,000 sites across 191 countries on what is now the most recognisable and lauded preservation lists.

The UK is home to 31 of them (35 including overseas territories) with two - Ironbridge Gorge and Pontcysyllte Aqueduct - here on home turf.

And marking World Heritage Day on April 18, travel experts at The Telegraph have ranked them all. 

According to the newspaper, the experts’ ratings "consider the visiting experience, how each site compares with others around the UK and the world, its value for money, the site’s preservation and the heritage it represents".

At the low, low end "in terms of tourism experience" were the remote Gough and Inaccessible Islands in the South Atlantic and Henderson Island in the South Pacific.

Given their incredibly remote location "visitor experience is non-existent", journalist Chris Leadbeater gave them 0/10.

At the other end of the scale came Stonehenge, Westmister Abbey, the Frontiers of the Roman Empire and St Kilda, given full 10/10 marks by the authors. 

For our own Ironbridge Gorge - which was inscribed on the World Heritage List in 1986 - travel journalist Greg Dickinson gave it a ranking of 7/10 and called a trip "essential" for anyone remotely interested in the Industrial Revolution.

"Shropshire’s valley of invention, or the 'Silicon Valley of its day', is a rite of passage for day-tripping schoolchildren across the country," Greg wrote.

"In truth, you could (and probably should) spend much longer than a day exploring its many sites – the tile museum, china museum, iron museum, Victorian town, Gorge museum, the bridge itself."

Ranking more favourably, and even out-ranking the Lake District, was the Pontcysyllte Aqueduct and Canal, which Greg gave a 9/10.

"If Ironbridge tells the story of the Industrial Revolution, then the Pontcysyllte Aqueduct brings it to life like a low-octane rollercoaster," he wrote.

"The entire stretch of canal listed by Unesco spans 11 miles, but for 1,000ft or so you are quite literally floating in mid-air. If it isn’t already on your to-do list, I would scribble it on pronto." 

The whole list is available to view online at: telegraph.co.uk/travel/destinations/europe/united-kingdom/best-worst-world-heritage-sites-ranked