In 1960, UNESCO’s campaigned the world over to save Egypt’s Abu Simbel from flooding by the Aswan Dam. This mammoth act of multinational cooperation galvanized the global community around heritage. France’s Culture Minister, André Malraux, said that our world “publicly proclaims [our] art as its indivisible heritage.” Over 50 countries funded half of the then $80 million cost to move the monuments out of harm’s way. This year marks the 40th anniversary of the World Heritage Convention, one of UNESCO’s most successful programs, arguably the most powerful vehicle for heritage preservation. Adopted by...