Machu Picchu, Peru

If ever a site deserved World Heritage status, it is Machu Picchu, built in the 1400s as a royal estate for the Inca emperor and abandoned as the Spanish decimated the empire. Fortunately, the conquistadors knew nothing of the emperor's isolated retreat; otherwise, they would have destroyed it. [2001]

Punda, Willemstad, Curaçao

Why is Willemstad a World Heritage Site? According to UNESCO, the capital of Curaçao is "an exceptionally well preserved example of a Dutch colonial trading settlement. . . . The unique setting in a natural harbour qualifies the Historic Area of Willemstad as a rare example of a historic port town laid out in a setting of natural waters." [2017]

Siem Reap, Cambodia

Angkor Wat, in addition to being a World Heritage Site visited by hoards of tourists, is also a Buddhist monastery. The management challenge is keeping the day-trippers from conflicting with the resident monks who prefer a milieu that is more prayerful than playful. [2016]

Tenerife, Canary Islands, Spain

Mt. Teide last erupted in 1909, and everything around the peak is volcanic in origin, including the Roque Cinchado, which has become a symbol of the Canary Islands. It's actually a remnant of an old volcanic surface from which the current cone arose. The national park is one of the most visited in the world, complete with a teleferico to the top. [2017]

Tenerife, Canary Islands, Spain

Given its shape, there is no doubt that Mt. Teide, now the focal point of a World Biosphere Reserve, is volcanic (active!) and high enough to rise above the tree line. The white cloud bank frequently obstructs views of the coast from the sunny interior. Do you remember the name of the cold current that chills the coast and precipitates the fog? [2017]

Saksaywaman, Peru

The fortress of Saksaywaman was built to protect the Inca's capital city, Cuzco. The Andesite stones here, as in Cuzco, were put together without mortar, and they are some of the largest ever used in pre-Columbian America.The igneous rock we call Andesite (not as light as rhyolite and not as dark as basalt) gets its name from the Andes. [2001]

Panama City, Panama

In the 16th century what as the most important European city on the Pacific coast of the New World? Panama. The ruins are now known as Panama Viejo. The Spanish needed a city here so they could haul Inca wealth across the isthmus and back to the Old World. A pirate attack in 1671 finally did it in, but the new Panama City was built only a few miles away. [2017]

Istanbul, Turkey

The Burnt Column is one of the most important architectural remnants of Istanbul's Byzantine past. It was dedicated by Constantine the Great in 330 AD to mark the site of the Roman Empire's new capital, the New Rome, on the site of Byzantium. Today, it gives its name to a stop on the city's metro: Çemberlitaş. [2010]

Suomenlinna Island, Finland

There are seven World Heritage sites in Finland (6 cultural, 1 natural). Their importance supersedes the category of national treasures. World Heritage sites constitute the common heritage of all humanity. Suomenlinna is "an outstanding example of general fortification principles of the 17th and 18th centuries," but it is also a recreational playground for Helsinki. [2005]

Siem Reap, Cambodia

The Bayon temple is the centerpiece of Angkor Thom, the 'great city' that was built as a new capital for the Khmer (or Cambodian) Empire in the 12th century. Its stone faces (upwards of 200) were probably modeled after the king, a Buddhist. What makes them so enigmatic are the smiles and closed eyes. You can see them but they can't see you. [2016]

Siem Reap, Cambodia

Angkor Wat began as a Hindu temple but transitioned to Buddhism in the 12th century. The five towers on level three represent the five peaks of Mount Meru, the center of the cosmological universe. They are also at the center of Cambodian identity: as illustrated by the country's flag. [2016]

Phnom Penh, Cambodia

During Pol Pot's reign of terror, Cheoung Ek was the site of one of Cambodia's "killing fields." One in four Cambodians lost their lives, including 9000 who were brutally hacked to death or otherwise mass murdered here, just 11 miles south of the capital. Their skulls are enshrined in a memorial stupa, which has become a praying place for humanity. [2016]

Jatiluwih, Bali, Indonesia

Around the village of Jatiluwih, rice terraces stretch from horizon to horizon. The planting is over and the harvest has yet to come, so these men must be repairing one of the paddy dikes. These agricultural landscapes are now on the World Heritage list, but a UNESCO site visit last year noted that "the pressure for land conversion remains significant." [2016]

Magelang, Java, Indonesia

Borobudur is the world's largest Buddhist temple. It was built in the ninth century and functioned for five hundred years. Then, it was abandoned and engulfed by Java's tropical forests. Now, it is Indonesia's top tourist destination, a focus of Buddhist pilgrimage, and a World Heritage site. [2016]

Seoul, South Korea

The Gyeongbokgung, or Northern Palace, was originally built in 1395 just a few years after the founding of the Joseun Dynasty. Within the palace, drums were a part of every ceremony and ritual. This one is a double-headed barrel drum in a cradle. [2016]

San Juan, Puerto Rico

Three Morro Castles made sure, for more than a century, that the Caribbean was a Spanish lake. Two were in Cuba and one was in Puerto Rico. Castillo San Felipe del Morro guarded the entrance to San Juan harbor, one of the best in the Antilles. Today, it belongs to the U.S. National Park Service and is listed as a World Heritage Site by the U.N. [2009]

Liverpool, England, UK

The pumphouse is now a pub. Having been built in 1878 on Liverpool's waterfront, it has transitioned from the Industrial Era to the Post-Industrial Era. When it was built, Albert Dock became famous for innovative design and technology. Now, it's a World Heritage Site and people pleaser. [2011]

San Juan, Puerto Rico

Thanks to the National Park Service, we know that "Spain's King Philip hired Field Marshall Juan de Tejada and Buatista Antonelli, a young Italian engineer, to help design a defense plan for the Caribbean." They decided to fortify 10 key sites, including the harbor of San Juan. Immediately, the geographer asks: Where were the other 9? [2009]

Delhi, India

In India, the two tombs to see are the Taj Mahal and Humayan's Tomb.  Both were built during the Moghul period, but the former was built by an emperor-husband for his wife, the latter by a wife for her emperor-husband.  Can you see the influence of Persian architecture and the resemblance between the two?  [2011] 

Ġgantija,Gozo, Malta

Ġgantija takes us back 5500 years, even before Egypt's Pyramid Age began. The era was neolithic (new stone age) and the construction was megalithic (built with large stones). In 1980, these and other temples in Malta were listed as World Heritage Sites by UNESCO. [2009]