London (CNN) -- Coal slag heaps up to 450-feet high may not seem the obvious candidates to join a list that includes the pyramids of Egypt, the Great Wall of China, and Yellowstone National Park.
But the remnants of a once-thriving mining industry in northern France have now been included in a roll call of the world's greatest landmarks.
The Nord-Pas de Calais Mining Basin has been designated a World Heritage site by the U.N.'s cultural organization, UNESCO, and is now ranked alongside nearly 1,000 sites across the globe considered to have outstanding value.
Coal was extracted from the region from the 17th to the 20th century, when it suffered an economic slump. Now, after a 10-year campaign, locals are aiming to promote as tourist attractions the old pits, railway stations, workers' estates and mining villages.
"It's important as a piece of history in that part of the world," said UNESCO spokesperson Susan Williams.
"It doesn't have to be pretty... but it does have to be of outstanding universal value, in other words important for the whole of humanity. The locals have been so excited about this. This is a site they are very appreciative of," she said.
In its summary, UNESCO said the mining region was a "remarkable cultural landscape" and provided "exceptional testimony to the exchange of ideas and influences regarding the extraction methods used for underground coal seams, the design of worker housing and urban planning, as well as the international human migration that accompanied the industrialization of Europe."
The Word Heritage Committee meets once a year to implement the convention defining the kind of natural of cultural sites that can be considered for the prestigious list.
The Calais basin is one of three mining sites that made the list this year. Among the 26 additions for 2012 were the Lakes of Ounianga in Chad, Africa, the Chengjiang fossil site in the Yunnan province of China, the decorated farmhouses of Halsingland in Sweden and the Margravial Opera House at Bayreuth in Germany.
Nominations for heritage status have to meet the UNESCO criteria agreed by member states and come up with a long-term management plan before they can be scrutinized and judged.
However, heritage status does not necessarily guarantee protection.
UNESCO Director-General Irina Bokova said news that mausoleums in Timbuktu, Mali, had been destroyed by Islamic militants was "extremely distressing" and called on all parties involved in the conflict to "protect this invaluable cultural heritage for future generations."
In 2001 the Taliban destroyed part of another of the world's treasures -- the huge Buddha statues in the Bamiyan Valley on the ancient Silk Road in Afghanistan.
Both of these sites are included on a list of 38 sites that are threatened.