Believe it or not, the oldest known list of �must-see places� was written over two thousand years ago. A greek historian, Diodorus Siculus, listed the seven wonders of the ancient world in 100 BC. Unfortunately, only the Pyramids of Giza survive from that list today. Since then, however, man has conceived of, and built many other landmarks and structures which can only be classified as wonders because of their scale and beauty.

The medieval period lasted from around 5 AD to 1500 AD, and many �wonders� from that time still exist and top the bucket lists of travelers from all around the world. It�s likely that the list of Wonders from the Medieval World actually came into being after the medieval period, and some of the sites listed on it were built slightly before it started. However, these structures are famous as medieval landmarks so, let�s take a look at the10 wonders from that time.

1. Hagia Sophia - Istanbul, Turkey

The foundations of Hagia Sophia were laid in 325 BC, in a pagan temple. Originally a small building, Byzantine emperor Justinian I extended it as a church in 532 AD. Ravaged by fires, riots, and earthquakes, the historical landmark has gone through many identity changes too. From a church to a mosque, to a museum, and finally back to a mosque again. It has seen all kinds of worshippers and tourists pass through its doors.

One constant legend associated with Hagia Sophia is the �perspiring� column. One of the mosque�s 107 columns has a hole in its base which is always wet. People touch it to pray for miracles, or in hope that they�ll receive �divine healing.�

2. Stonehenge - Wiltshire, England

One of England�s most popular tourist destinations, Stonehenge�s existence, and construction have baffled historians and scientists alike. Built during the Neolithic and Bronze Ages, the landmark is made up of around a hundred colossal stones, placed upright, in a circular pattern. The outer stones are sandstone slabs, which probably came from closeby quarries, but the inner stones are traced back to Wales, two hundred miles away.

Built in prehistoric times, it remains a mystery how the stones were hauled so far, and why. Some believe Stonehenge was a cemetery, some think it was once a site for religious ceremonies, and some feel it may have been an observatory of sorts, to predict weather patterns, eclipses, and solstices. 

The most interesting theory by far though, is that Merlin, the magician in King Arthur�s court, used magic to collect the stones and build Stonehenge.

3. Cairo Citadel - Cairo, Egypt

In the 12th century, Ayyubid ruler Saladin built a fortified citadel on the Muqattan hill in Cairo. He felt the location was perfect as it was high enough to observe what was happening in the city, and in this way he could protect his kingdom from Crusaders. Saladin employed the best, most modern techniques of the time to build the fortress. For the next seven hundred years, the citadel remained the seat of the Egyptian government, but in 1860, the ruler moved his residence to a palace in some other area of Cairo.

The citadel remains a popular tourist attraction, with three historic mosques, the most famous of which is named the Mosque of Muhammed Ali. Museums and towers constructed in the citadel also remain popular with tourists.  

4. Kom el Shoqafa Catacombs - Alexandria, Egypt

The necropolis was built in the 2nd century AD, for Egyptian royalty. The pharaohs' mummies would be laid to rest in this �theater of the dead.� Kom el Shoqafa literally means �mound of shards,� or �potshards,� because of the shards of terracotta pots and containers left in the area by people visiting the tombs. They brought food and drink in the containers but would break them before leaving because they did not want to carry them back for fear of bad luck.  

A fusion of Greek, Egyptian, and early Roman architecture, the catacombs consist of several chambers and levels which could hold up to 300 corpses at a time. The dead bodies were supposedly lowered down a circular staircase, which tourists can use to go down. The third level though is inaccessible because of leaks and flooding. 

5. Great Wall of China - Beijing, China

The Great Wall of China is actually a number of small walls built, rebuilt, and maintained, between the 5th century BC and 16th century AD, to protect China from invaders and enemies. Over thirteen thousand miles in length and the largest human-made structure in history, the Wall stretches from Liaodong in the east to Lop Lake in the west, and the Sino-Russian border in the north to Tao River in the south.

Workers used stone, brick, wood, and packed earth in its construction and built watchtowers, smoke-signaling stations, and military accommodations along its length to make it harder for invaders to penetrate it. More than one-third of the wall is in ruins or completely destroyed now, but the Ming dynasty built the most notable sections of it, which still stand today. 

6. Leaning Tower of Pisa - Pisa, Italy

The famous Leaning Tower of Pisa was never meant to lean. Its construction began in 1173 and workers noticed the lean when it was only three stories high. They were trying to figure out how to fix the problem, caused by a poorly-laid foundation when war broke out in Italy. Construction resumed 100 years later.

The foundation had settled but the engineer�s decision to build the new levels on the taller side caused it to lean further. The tower continued to be built until the 14th century and bells were installed in it over the next 400 years. Italians closed the tower to the public in 1990, so engineers could try and fix it. It reopened in 2001 and is supposed to be safe for another 200 years.    

7. Cluny Abbey - Cluny, France

The Cluny Abbey was founded in 910 AD when Duke William I of Aquitaine bestowed his hunting preserve to the Benedictine monks so they could establish and run the place of worship independently. The Abbey had three incarnations, but the first two versions were wiped out. Cluny III, built in the 11th century, was the largest, most powerful Christian church for centuries. It controlled over 10,000 monks, had the richest library in Europe, and contained expensive artwork, with solid silver and gold candelabras, and many other items of luxury.

Poor governance eventually led to the Abbey�s downfall and most of it was destroyed during the French Revolution because it was seen as a symbol of excess. The ruins remain and are a major tourist attraction.

8. Ely Cathedral - Cambridgeshire, England

Located in the small town of Cambridgeshire, Ely Cathedral is one of the longest cathedrals in England. Originally founded as an abbey church in 673 AD by St. Etheldreda, it was destroyed during Viking raids. Its restoration began in 970 AD and with time it became one of England�s most successful abbeys.

The cathedral is called the �ship of the Fens� because of its structure and the way it rises above the landscape. Its tallest tower, the West tower looks like a ship�s prow, and its most famous tower is the Octagon tower, which is shaped like a lantern and is considered a medievel engineering marvel. The freestanding Lady Chapel and famous stained glass museum are also a must-see for tourists visiting the cathedral. 

9. Colosseum - Rome, Italy

After Nero�s stormy rule, Roman emperor, Vespasian decided he needed to appease the Roman public and bring some stability to his empire. He designated Nero�s palace as the site for an amphitheater, as a gift for his subjects. The Colosseum was unique in its architecture as it was built as a freestanding structure made of stone and concrete. It took ten years to build and was the largest amphitheater in the Roman world.

Its opening was marked by a 100-day festival of gladiatorial combats and games. It could fit 50,000 spectators at a time and was actively used for four centuries until public tastes changed. While two-thirds of the majestic structure has fallen to ruin because of earthquakes, weather, and even vandalism, the Colosseum remains a remarkable landmark and a defining part of Rome. 

10. Porcelain Tower - Nanjing, China

The Ming Dynasty constructed an entire tower made of white porcelain bricks in the 15th century. Constructed as part of the temple complex Bao En Si (Temple of Repaid Gratitude) the porcelain tower was a nine-story pagoda, built in seven years on the south bank of the Yangtze River.

Unfortunately, a bolt of lightening destroyed the tower�s top three stories in 1801, and though these were reconstructed, Taiping Rebels destroyed it in the mid-nineteenth century because they were Christians and did not want a Buddhist pagoda on the land they took over. However, a modern, steel reconstruction of the tower opened to the public in 2017. The richest man in China, Wang Jianlin, funded its reconstruction, and the construction of a futuristic Buddhist museum surrounding it.  

It�s fascinating how humans have created structures that have stood for centuries, and become synonymous with the cities they�re in. So, next time you�re planning a trip to one of these places, you know at least one landmark you have to put on your must-see list.