50 fascinating cultural UNESCO World Heritage Sites around the world

The Karnak Temple Complex, which was developed over the course of more than 1,000 years, was once considered the largest and most important religious complex in Egypt. Its most important building was the Temple of Amun-Re, which was believed to be the sun god's earthly dwelling.

Brought to the world's attention by explorer Hiram Bingham in 1911, Machu Picchu is believed to be the Inca Empire's most amazing architectural feat. Composed of temples, palaces, terraces, monuments, complexes, and water channels, the citadel receives over 1 million visitors each year.

The Pamukkale thermal pools have been a popular tourist destination since antiquity; wealthy Romans used to retire here in order to enjoy the healing waters as frequently as possible. Their cottony appearance (the word Pamukkale literally means "cotton castle") is caused by the high levels of calcium carbonate in the mineral water.

Built in the 12th century, Spiš Castle was an important political, cultural, and economic center for the Kingdom of Hungary. In the centuries since, several movies have been filmed on the castle's grounds, including "Dragonheart," "The Lion in Winter," and "The Last Legion."

The Potala Palace is located on Red Mountain, some 12,000 feet above sea level. For hundreds of years, the palace was the winter residence of the Dalai Lama and, as a result, is an important location in the history and development of Tibetan Buddhism.

The first building one sees when entering the ancient city of Petra is Al-Khazneh, or the Treasury, as it is known. Built in the first century AD, archaeologists believe the intricately decorated building most likely served as a royal tomb.

This wood and earthen fortress used to be a popular stop on the caravan route between the Sahara desert and Marrakech in Morocco. Thought to be built in the 17th century, the well-preserved citadel is still home to five families.

Founded in the ninth century, the Medina of Fez is one of the best-preserved historic towns in the Arab world. Its maze of narrow streets is also home to al-Qarawiyyin, which was founded in 859 and is considered by many to be the oldest continuously operating university in the world.

In 79 AD, Mount Vesuvius erupted, burying the Roman towns of Pompeii and Herculaneum and killing an estimated 2,000 to 16,000 people. In an ironic twist of fate, the massive amounts of volcanic mud, debris, and gases that claimed these lives almost perfectly preserved the towns, giving modern-day archaeologists an unrivaled glimpse at what life was like in ancient times.

Meteora, which means "suspended in air" in Greek, is the perfect descriptor for these monasteries built on top of a complex of rock pillars (some of which rise roughly 400 meters above the valley floor). The area was first used by monks in the ninth and 10th centuries, and today six of the 24 original monasteries remain active.

The Piazza San Pietro (or St. Peter's Square) was constructed between 1656 and 1667 in front of the basilica built over the tomb of St. Peter (one of Jesus' apostles and, according to Catholic tradition, the first pope). Massive in scale, it is 320 meters long, 240 meters wide, and can hold 300,000 people.

Theories abound as to who constructed Stonehenge, ranging from the wizard Merlin to aliens. First built nearly 5,000 years ago, most experts agree the arrangement of menhirs (which took an estimated 20 million hours to construct) is either a religious site or a scientific observatory.

Once home to the supreme patriarch of Ayutthaya's "city-dwelling" Buddhist sect, Wat Mahathat predates the founding of Bangkok. It was long believed that the complex housed a relic of the Buddha, and in the 1950s, excavators found one: a bone fragment about the size of a grain of rice, tucked inside a small reliquary.

First buried in 210 BC, these terracotta warriors, which surround Emperor Qin's tomb, weren't discovered until 1974. Thousands of soldiers, each with a unique facial expression, are arranged by rank, guarding the still uncovered final resting place of the man who united China.

Built sometime in the first century, the Pyramid of the Sun (pictured) and the Pyramid of the Moon are among the largest structures in ancient America. The crowning achievements of Teotihuacan culture, experts aren't sure exactly what the buildings were used for, as very few records remain.

Pictured above is the Bryggen harbor district in Bergen, Norway, one of Northern Europe's oldest port cities. The colorful houses are made of wood, and though several fires over the centuries have destroyed many of the original buildings, they have always been rebuilt using traditional materials and construction techniques.

Construction on the Benedictine abbey Mont Saint-Michel began around the 11th century. Romanesque and Gothic in style, the stunning church has been a popular pilgrimage destination over the years despite its difficult-to-access location (on a rocky islet that's exposed to tides coming from both Normandy and Brittany).

Built in the form of Krishna's crown, the five-story Hawa Mahal palace has a whopping 953 windows. These windows, as well as their surrounding latticework panels, allow for breezes to flow freely throughout the palace, making it an ideal summer dwelling and earning it the nickname "The Palace of Winds."

Located in Meroë, the capital city of the Kingdom of Kush, these pyramids were built more than 2,000 years ago. Built in the Nubian style, the roughly 200 pyramids (which served as royal burial sites) still exist in this city, more than in the entirety of the country of Egypt.

One of the oldest towns in sub-Saharan Africa, Djenné is an excellent example of ancient adobe architecture. The once-thriving city was a key stop on trans-Saharan trade routes as well as a thriving center for Islamic scholarship.

Nomadic herders have called the Orkhon Valley home for more than 2,000 years. The area includes the ruins of Karakorum, the 13th-century capital of the Mongol Empire, as well as Erdene Zuu, which was built in 1586 as Mongolia's first Buddhist monastery.

The Boudhanath Stupa, a meditative monument and offering site, is one of the most significant pieces of Buddhist architecture. Built in the 14th century, the dome and tower are covered in pairs of eyes meant to remind visitors of the all-knowing nature of Buddha.

One of the longest construction projects of all time, the Great Wall of China was continuously worked on from about 220 BC, when China's first Emperor Qin Shi Huang ordered existing sections to be joined together to create a universal defense system, to the 17th century. In all, the wall measures 20,000 km (or 12,427 miles) in length.

Another construction project that's taken an abnormally long time to finish, La Sagrada Familia (or the Church of the Sacred Family) began in 1882 and topped out its tallest tower in 2026, making it the tallest church in the world. The Gothic-with-a-twist basilica was designed by the famous architect Antoni Gaudí, and has been described by critics as "a feast for the eyes and full of symbolism."

The crossroads of ancient civilizations, Palmyra, by nature of the fact that it was a major city on a trade route, linked China, Persia, and India with the Roman Empire. Its ancient ruins were rediscovered in the 17th and 18th centuries and, after being nearly destroyed by ISIS in the 2010s, conservators have begun rebuilding, starting with the site's museum.

Kew Gardens, a botanic garden located in southwest London, has one of the largest and most diverse collections of living plants in the world. Princess Augusta, the mother of King George III, began the garden back in 1759, and various royals and government agencies have been adding to it ever since.

Located on the Quinta da Regaleira, a private estate in Sintra, Portugal, the Initiation Well is not a water source but an inverted underground tower built in the early 1900s and steeped in Knights Templar and Masonic symbolism. Visitors to the site today can retrace the steps of the initiation rituals it's rumored to have hosted.

Some 1,300 years ago, the Hani people began the engineering marvel that is the Honghe Hani Rice Terraces. Covering about 160 square kilometers, the terraces are arranged in such a way that water can travel from the top of the Ailao Mountains to the Hong River, weaving around the 82 villages that are incorporated into the area.

Commissioned by Emperor Gebre Meskel Lalibela, the Bete Giyorgis (or Church of St. George) was one of 11 churches built as part of a new "Ethiopian Jerusalem," according to Atlas Obscura. Created from a single piece of stone (it was carved from the top down), the church is the most elaborate surviving example of the project.

Built between 37 and 4 BC by King Herod, Masada is a palatial fortress overlooking the Dead Sea. Around 66 AD, it was co-opted by a group of Jews who, having been expelled from their homes by the Romans, used it as a final stronghold, holding out until 73 AD before they chose to die rather than fall into the hands of their persecutors alive.

In the sixth century, a group of Christian monks moved to the jagged rock, Skellig Michael, just off the coast of County Kerry in Ireland. They lived and prayed in beehive-shaped huts (like the one pictured above), only abandoning the settlement in the 13th century.

One of the oldest demarcated wine regions in the world, folks have been growing grapes in the Douro Valley for some 2,000 years. The primary product of these vineyards is port, a strong and sweet wine that is often served with dessert.

Over the course of about 1,000 years, several pre-Hispanic societies carved massive geoglyphs (pictures of figures, animals, plants, and bugs, as well as geometrical shapes) into the hillsides and flat, arid ground of the Peruvian plains. The how and why of these drawings remain a mystery, but they demonstrate a religious and social homogeneity among these early cultures.

Two enormous and highly decorated Buddhas were carved into the mountainside outside Bamiyan, Afghanistan, between 550 and 615 AD by the Gandhara civilization. Commonly referred to as the Bamiyan Buddhas, the popular pilgrimage destinations stood for more than 1,000 years, until the Taliban destroyed them in 2001.

Located on the island of Java, the Borobudur Temple complex was built during the Syailendra Dynasty between the eighth and ninth centuries. It was an important place of worship until sometime between the 10th and 15th centuries, when it was inexplicably abandoned, only to be rediscovered in the 19th century.

An imposing medieval castle and fortress, the Hohensalzburg castle was built at the behest of the prince-archbishops (archbishops who also ruled principalities) in the late 11th century. Set atop a steep, conical rock, the castle has never been captured by foreign troops.

Khiva, Uzbekistan was once a major town on the Great Silk Road. Believed to have been founded by one of Noah's sons, Shem, the city quickly became an important center of Islam with 94 mosques and 63 madrassahs.

On an island in Lake Onega lies a group of wooden buildings known as the Kizhi Pogost. The centerpiece of these buildings is the Church of the Transfiguration, a Russian Orthodox house of worship, which is rumored to have been built with a single ax and without a single nail.

At one point, it was believed that 100 people lived in the 150 rooms and 23 kivas (rooms for religious rituals) located in Cliff Palace. One of the best-preserved examples of the cliff-side homes inhabited by ancient Pueblo people, the palace is made of sandstone, mortar, and wooden beams.

Historic Prague is one of the best-preserved medieval cities on earth. Set along both banks of the Vltava River, the city hasn't fallen victim to any large-scale renewals or demolitions, which means it remains, largely, exactly as it was during the 11th-18th centuries.

Forces of erosion and large quantities of volcanic material are responsible for the mountain ridges, valleys, and "fairy chimneys" that give Cappadocia, Turkey, its unique landscape. The area, which is often visited by hot air balloon tour, is home to several underground cities and churches that are carved directly into the rock.

Thingvellir, Iceland, is one of the few places in the world where the rift between the North American tectonic plate and the Eurasian tectonic plate is visible above sea level. This unique geological attribute has lent the area a sacred feeling, and, as a result, some of the biggest moments in the country's history (like its renunciation of the Norse pagan belief system for Christianity and its declaration of independence from Denmark) have taken place here.

Friedrich Georg Wilhelm von Struve, a German-born scientist, used a chain of survey triangulations (which begin in Hammerfest, Norway, and end in the Black Sea) to help establish the exact shape and size of the earth. Stretching through 10 countries, these 34 station points (called the Struve Geodetic Arc) are an incredible example of global collaboration in the name of science.

The undisputed symbol of France, the Eiffel Tower is about 1,083 feet tall. The "Iron Lady," as she is often called, receives over 6 million visitors each year, the vast majority of whom are international travelers.

The only living Native American community to be dubbed a UNESCO World Heritage Site and National Historic Landmark, Taos Pueblo is believed to be one of the oldest continuously inhabited settlements in the United States. For over 1,000 years, the Taos Indians have lived in these adobe dwellings, and most of the current buildings were constructed between 1000 and 1450 AD.

Alberobello, in the Puglia region of Italy, has the highest concentration of trulli houses anywhere in the country. The round dwellings are made of limestone boulders and topped with dome-, pyramid-, or cone-shaped roofs made of limestone slabs.

Deemed one of the most scenic spots in all of Japan, Miyajima is a holy place in the Shinto religion, dedicated to the gods that protect people from sea disasters and wars. The earliest shrines on the island were built around the sixth century, but the shrine pavilion that's there today dates to the 12th century, and the enormous torii gate was built more recently, in 1875.

In the Bay of Kotor, Montenegro, there are two small islands. One of them, the man-made Our Lady of the Rocks, boasts a Catholic chapel (first built in 1632 and expanded in 1722) that houses a 15th-century icon of the Virgin Mary.

No city in the world boasts as many artistic riches as Venice, Italy. Almost every building in the 118-island city contains works by visionaries like Titian, Veronese, and Tintoretto.

From the 15th to the 19th centuries, Hoi An was a bustling trading port, drawing merchants from China, Japan, and Europe. Its well-preserved wooden shophouses, temples, and Japanese Covered Bridge still reflect that blend of cultures.