UN cultural agency UNESCO has granted its coveted World Heritage status to a vast and ancient Inca road system spanning six countries in South America.

The listing of the Qhapaq Nan roads will boost efforts to preserve and promote the network – an engineering marvel comparable to the vast road system of the Roman Empire.

Delegates at UNESCO’s World Heritage Committee voted on Saturday to grant the status at a gathering in Doha, where they are considering some 40 cultural and natural wonders for inclusion on the UN list.

Covering about 30,000 kilometres and constructed by the Incas over centuries, the system has long connected the peoples of Argentina, Bolivia, Chile, Colombia, Ecuador and Peru.

The six nations came together to submit the bid for its nomination and have vowed to work in concert to preserve and restore the road system.

Inclusion on the list has significant economic implications as a World Heritage Site is eligible for financial assistance toward preservation and the status is also a powerful draw for tourists.

“This is a recognition of one of the most important sites in the world,” Luis Lumbreras Flores, who is responsible for the Qhapaq Nan project at Peru’s culture ministry, said.

The road system, which reached its height in the 15th century, linked the Incan capital Cusco in present-day Peru with the vast reaches of the empire.

“The Qhapaq Nan by its sheer scale and quality of the road is a unique achievement of engineering skills in most varied geographical terrains, linking snow-capped mountain ranges of the Andes … to the coast, running through hot rainforests, fertile valleys and absolute deserts,” UNESCO said in documents presented at the Doha meeting.

“It demonstrates mastery in engineering technology,” UNESCO said, calling it “an exceptional and unique testimony to the Inca civilisation”.