How UNESCO World Heritage Sites Are Restored and Preserved

Sites that are not properly maintained can end up on the "Danger List"

Dubrovnik Harbor
Samantha T. Photography / Getty Images

We’re dedicating our November features to arts and culture. With cultural institutions around the world in full swing, we’ve never been more excited to explore the world’s beautiful librariesnewest museums, and exciting exhibitions. Read on for inspiring stories on the artist collaborations that are redefining travel gear, the complicated relationship between cities and spontaneous art, how the world’s most historic sites maintain their beauty, and an interview with mixed media artist Guy Stanley Philoche.

There's no more tremendous honor for a cultural or natural site than being inscribed on the UNESCO World Heritage List. Since 1972, the United Nations Educational, Scientific and Cultural Organization (UNESCO) has been bestowing the prestigious designation to properties around the world that have "outstanding universal value" to humanity, whether that's a monumental engineering achievement like Egypt's many pyramids, or breathtaking natural beauty, as found in the Grand Canyon.

The benefit of the distinction is simple. Earn UNESCO World Heritage status, and the public awareness of a destination (translation: tourism numbers and dollars) will rise. But perhaps more importantly, inscription on the list requires governing bodies, both local and international, to commit to preserving a site in the face of climate change, war, and overtourism, among other threats.

UNESCO World Heritage status isn't permanent, and if a site's quality deteriorates, it might have its designation revoked—it happened to the British city of Liverpool this summer. At an annual meeting, a UNESCO committee removed Liverpool from the World Heritage List "due to the irreversible loss of attributes conveying the outstanding universal value of the property." According to UNESCO evaluators, new developments ruined the maritime city's primary attribute, the historic waterfront district.

Such a demotion doesn't happen overnight. UNESCO first puts at-risk sites on its Heritage In Danger list—Liverpool was added in 2012—which signals to the sites' stakeholders that urgent measures must be taken to protect them. Currently, 52 sites, including the Great Barrier Reef in Australia and the city of Palmyra in Syria, sit on the list.

But all hope is not lost for those properties. So far, only three former World Heritage Sites have had their status stripped. Far more have been removed from the danger list due to successful preservation.

There's no more tremendous honor for a cultural or natural site than being inscribed on the UNESCO World Heritage List

Take, for instance, the Old City of Dubrovnik. The "Pearl of the Adriatic" was inscribed to the UNESCO World Heritage List in 1979 for its impressive medieval architecture, including its famous wall, built between the 12th and 17th centuries. But in 1991, it was bombarded in the Siege of Dubrovnik during the Croatian War of Independence; more than 600 artillery shells damaged some 56 percent of the Old Town's buildings, and more than 200 people died.

UNESCO promptly placed Dubrovnik on the World Heritage in Danger List, and restoration work began immediately—even during the seven-month siege itself. "After each episode of shelling, local inhabitants, with help from the Institute for the Protection of Cultural Monuments and the Institute for the Rehabilitation of Dubrovnik, set to work making repairs. Bituminous roofing was laid on a temporary structure of thin planks where roof-strips had been destroyed. Where possible, tiles were replaced temporarily," according to a 1994 article published in The George Wright Forum, a journal about parks, protected areas, and cultural sites. But the permanent restoration of the city took years.

Croatian groups partnered with UNESCO, the International Council on Monuments and Sites (ICOMOS), and the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM) to devise a strategy for the restoration, which included setting up training programs to educate restorers in historical construction and decoration methods, from stonework to painting.

Unsurprisingly, such large-scale restorations require extensive financial and technical resources. Though UNESCO does have a small budget to contribute to such projects, the primary burden falls on the manager of a site, whether a private organization or the local or national government—or, most typically, a combination of all three. In the case of Dubrovnik, the Croatian government contributed some $2 million annually to restoration work in the decade following the siege; UNESCO provided a one-time donation of $300,000, while dozens of other organizations also participated in fundraising for the cause.

International contributions also frequently come into play. After the Angkor Archaeological Park in Cambodia was added to the World Heritage in Danger list in 1992 (for illegal excavations, pillaging, and landmines), Japan established the Japanese Government Team for Safeguarding Angkor (JSA) to oversee restoration projects; as of 2017, Japan had contributed more than $26 million across four projects, sending 800 experts to the site over 23 years. The World Monuments Fund, a private international non-profit, has had a presence at Angkor since 1991, establishing the Center for Khmer Studies, a conservation research and training facility.

Low Angle View at Ta prohm Temple Against Sky
sakchai vongsasiripat / Getty Images

Because of their extensive conservation projects, both Dubrovnik and Angkor have been removed from the World Heritage in Danger list in 1998 and 2004, respectively. But that doesn't mean preservation is complete—both sites are continually undergoing restoration. And, in fact, they now have to deal with another threat: overtourism.

While tourism is essential for the financial health of many World Heritage Sites, especially when it comes to funding continual restoration projects, it can become problematic if not kept in check. Dubrovnik's Old Town was famously plagued by crowds of up to 10,000 cruise ship tourists who would flood the city in a single day, many of whom were drawn by its status as a "Game of Thrones" filming location. Infrastructure-wise, Dubrovnik couldn't handle those numbers, and the quality of a visit to the city was diminished, prompting UNESCO to advise city officials to restrict cruise passenger traffic. In 2019, the mayor of Dubrovnik capped the number of ships docked at a time at just two, with no more than 5,000 passengers between them.

Angkor, too, struggles from overcrowding, but unlike Dubrovnik, there are no tourism caps in place yet. (The site did have a pandemic-induced reprieve—Cambodia is currently closed to international visitors, though a phased re-opening begins at the end of November.) UNESCO is watching closely. A 2021 state of conservation analysis flagged that management systems are a threat to Angkor, as is uncontrolled urban expansion.

So while earning UNESCO World Heritage status is undoubtedly an honor for a destination, it also ensures a commitment to restoration and preservation on both a local and global scale. And given the challenges threatening the world's most valuable cultural and natural properties, that's never been more important.