Singapore is known as the "garden city," so it's no surprise that Singapore's botanic gardens were listed as a UNESCO World Heritage Site in 2015. The beautiful 189-acre tropical garden has become a world-class scientific institution, used for research and plant conservation. Older than the city itself, Singapore Botanic Gardens started as a British tropical colonial botanic garden in 1859.

Beijing’s Temple of Heaven may sound like a divine paradise, but it was actually built as an imperial sacrificial altar. In the midst of gardens and pine woods, the 15th-century temple complex was laid out to symbolize the connection between heaven and Earth. This is where Ming and Qing dynasty emperors made animal sacrifices, praying for good harvests.

It’s rare that bridges take center stage the way that the Old Bridge (Stari Most) of Mostar, Bosnia, does. The town itself was named for the 16th-century bridge, which is also a UNESCO World Heritage Site. And for good reason: The simple, gorgeous stone arch stretches over the valley of the Neretva River with fortified towers on either side, a spectacular technological achievement of the Ottoman era.

Mistaken Point got its curious name from the rocky coast and rough Atlantic waters surrounding the point in the southeastern corner of Newfoundland. Difficult to navigate, they produced more than 50 shipwrecks over the years. Today, however, Mistaken Point is a UNESCO World Heritage Site for another significant reason: The oldest fossils of multicellular life on Earth were discovered here. The fossils date back to the Ediacaran period, approximately 565 million years ago.

No, that’s not a mirage; that’s Al-Ahsa Oasis, the world’s largest self-contained oasis, as recognized by Guinness World Records. Situated in southeastern Saudi Arabia about 40 miles inland from the Persian Gulf, the oasis (which is fertile land with a water source in the midst of a desert) is home to over 2.5 million palm trees spread across 32.9 square miles. It became a UNESCO World Heritage Site in 2018.

Some tourists want what they can’t have. So, with a name like the Forbidden City, it’s no surprise that China’s imperial palace takes the top spot of the most visited UNESCO World Heritage Sites. Averaging 15 million annual visitors since 2012, the Ming Dynasty palace complex in Beijing not only housed emperors, but was once the cultural and political center of China.

The Wieliczka and Bochnia Royal Salt Mines in southern Poland operated from the 13th century until the late 20th century. What was once a major industrial operation is now a UNESCO World Heritage Site that features an elaborate underground museum, chapels, and galleries of sculptures carved from salt. Some areas of the mines are located more than 1,000 feet underground.

Located at the gateway to the Sahara Desert, Timbuktu was the intellectual and spiritual capital of Africa during the 15th and 16th centuries. The city, which became a UNESCO World Heritage Site in 1988, is home to three great mosques that helped spread Islam throughout the continent: Djingareyber, Sankore, and Sidi Yahia.

The crystalline waters of Lake Titicaca aren't just notable for their location high in the Andes Mountains — at 12,500 feet above sea level, Lake Titicaca is the highest navigable lake in the world and the largest freshwater lake in South America, covering about 3,200 square miles along the border between Peru and Bolivia. It is estimated to be about 3 million years old and one of just 20 ancient lakes remaining on Earth.

Considering its long and storied history, it might come as a surprise that London counts only four UNESCO World Heritage Sites within its city limits. They are the Palace of Westminster, Westminster Abbey, and Saint Margaret's Church (together forming one site); the Royal Botanic Gardens at Kew; the Tower of London; and Maritime Greenwich, where you can straddle the prime meridian with one foot in each hemisphere.

Québec is the only North American city to have preserved its ramparts and other defensive works such as gates and bastions. The first thing visitors notice in Old Québec is the colorful Château Frontenac, a historic hotel that towers over this picturesque quarter. Tourists can also visit the 200-year-old Citadelle de Québec, the largest British-built fortress in North America, as well as a 400-year-old monastery.

Today, Italy boasts a whopping 55 UNESCO World Heritage Sites, but it all started in Valcamonica. Located in the Lombardy region of northern Italy, this valley boasts nearly 140,000 prehistoric cave drawings and became Italy's first UNESCO World Heritage Site in 1979. The petroglyphs represent approximately 8,000 years of human history, providing a unique insight into the evolution and development of human societies.

The Clash spelled it with a “C” when they wailed to “Rock the Casbah” in their 1982 hit, but you can still visit the famed Kasbah of Algiers on the coast of Algeria. This UNESCO World Heritage Site is honored as an outstanding example of an early settlement in the Mediterranean Muslim culture. The area holds many preserved examples of traditional homes, palaces, hammams, and mosques.

A select few cities and towns are so full of cultural experiences and landmarks that their entire area has been named a UNESCO Heritage Site. Quito, the capital city of Ecuador, is one such cultural treasure. The city was founded in the 16th century on Incan ruins, and it remains one of the best-preserved and least-altered historic cities in South America.

Located in the hills outside Lisbon, Portugal, Sintra feels like stepping into a fairy-tale. The entire town was named a UNESCO World Heritage Site for its display of European Romantic architecture, including Pena Palace. It was the creative dream of King Ferdinand II, who transformed the site of a former monastery into the dazzling castle in 1854.

The Maya civilization once covered a huge swath of southern Mexico and the northern parts of Central America, and Chichen Itza was once one of its largest cities, established around 600 CE. Today, Chichen Itza, located in the Yucatán Peninsula, is one of Mexico’s most important archaeological sites and a UNESCO World Heritage Site. More than 2 million tourists visit annually to be awed by what the Maya built.

The Roman Colosseum may loom large in history, but it’s not one of the 12 original UNESCO World Heritage Sites. The first list, created in 1978, included sites such as the historic center of Krakow, Poland; Geyser Basin in Yellowstone National Park; the archaeological site of L’anse Aux Meadows in Canada; Ethiopia’s rock-hewn church in Lalibela; and Germany’s Aachen Cathedral.

The UNESCO-listed city of Bath was founded by the Romans in the first century CE on top of natural hot springs, which were used as a thermal spa. In the 18th century, three different King Georges (I, II, and III) helped preserve the Romans' legacy, and now the site is considered to be the most important collection of Roman remains north of the Alps.

Surrounded by Rome, Vatican City is the world’s smallest sovereign nation, at just 0.17 square miles in size. At its center is St. Peter’s Basilica, the world’s largest Catholic church, which contains the tomb of the Apostle Saint Peter. It features an impressive collection of Renaissance and Baroque art and architecture, including Michelangelo’s Sistine Chapel and works by Raphael and Leonardo da Vinci.

As of 2021, there are 1,155 places in 167 countries that are protected by the United Nations Educational, Scientific and Cultural Organization (UNESCO) for having cultural, historical, or other significance. Italy has the most sites, with 58, including the historic city centers of Rome and Florence, the Dolomites, the city of Verona, and the site of Leonardo da Vinci’s painting “The Last Supper”.