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Tiwanaku, Bolivia -

Tiwanaku is one of the finest examples of pre-Columbian civilization in South America, and certainly one of the largest. It's estimated the ancient city was inhabited by 10,000 to 20,000 people in 800 CE. The site is located 44 miles (70 km) from La Paz.

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Persepolis, Iran -

Situated in the plains of Marvdasht in Iran's Fars province, Persepolis was founded in the 6th century BCE as the ceremonial capital of the Achaemenid Empire. A compact but highly ornate city, Persepolis had a population of nearly 44,000.

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Ecbatana, Iran -

The capital of the Median kingdom, and the first capital in Iranian history, Ecbatana at one point housed a population of 100,000, around 400 BCE. The ancient ruins are set near the modern-day city of Hamadam.

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Tikal, Guatemala -

Tikal, the ruins of an ancient Mayan city likely to have been called Yax Mutal, are now part of Guatemala's Tikal National Forest. At its peak, this large lowland city was home to 100,000 souls.

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Ur, Iraq -

Recorded in written history as a city-state in 2100 BCE, Ur was an important Sumerian stronghold of strategic significance, sited as it was where the Tigris and Euphrates rivers empty into the Persian Gulf. A population of more than 100,000 made Ur one of the largest cities in the world.

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Edessa, Turkey -

Founded during the Hellenistic period, Edessa was an ancient city in Upper Mesopotamia that by 500 CE numbered a population of around 100,000. The city today is known as Urfa.

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Nicomedia, Turkey -

Nicomedia is the ancient name for Izmit. The city was built during the 3rd century BCE and was later the eastern and most senior capital city of the Roman Empire between 286 and 324 CE, when its population had risen to 100,000.

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Emerita, Spain -

Emerita is the ancient name for Mérida, a city in Spain's Badajoz province. Founded as a Roman colony in 25 BCE under the order of the emperor Augustus, Emerita flourished as a garrison town and eventually numbered a population in excess of 100,000.

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Jerusalem, Israel -

One of the oldest cities in the world, and considered holy to the three major Abrahamic religions (Judaism, Christianity, and Islam), Jerusalem was first settled in 3500 BCE. From about 300 BCE through 600 CE, the city's population stood at around 100,000.

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Samarkand, Uzbekistan -

Among the oldest continuously inhabited cities in Central Asia, ancient Samarkland prospered from its position on the Silk Road, a fact that also saw its population reach 100,000 in 300 BCE.

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Trier, Germany -

The oldest city in Germany was founded by the Romans in the late 1st century BCE as Augusta Treverorum. Emperor Constantine made the city the capital in the latter years of the Roman Empire, when its citizens numbered 110,000.

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Suzhou, China -

Founded in 514 BCE, Suzhou later became the largest non-capital city in the world, reaching a peak of 120,000 in 600 CE. Little remains of the ancient city, its foundations hidden by modern Suzhou, part of the Yangtze Delta megalopolis.

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Smyrna, Turkey -

The ancient Greek city of Smyrna rose to prominence due to its location on the Aegean Sea coast. The city was founded in 3000 BCE and reached metropolitan proportions during the period of the Roman Empire, when 125,000 people resided within its boundaries. Since the 1930s the city's name has been Izmir.

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Taxila, Pakistan -

Old Taxila in present-day Pakistan was once the capital city of ancient Gandhāra, situated on the eastern shore of the Indus River. It was founded in a strategic location along the ancient "Royal Highway," one of Asia's oldest and longest major roads. Its population in 100 BCE was approximately 150,000.

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Teotihuacan, Mexico -

Teotihuacan, an ancient Mesoamerican city located 30 miles (48 km) northeast of present-day Mexico City, was settled around 400 BCE and 800 years later had become the most powerful conurbation in the region. At one point 150,000 people lived in Teotihuacan, making it at least the sixth-largest city in the world during its epoch.

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Thebes, Egypt -

Thebes enjoys a reputation as one of the most famous ancient cities. Located along the Nile, it was a religious center and the most venerated city during many periods of ancient Egyptian history. Its peak population period was 1200 BCE, when 150,000 called it home.

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Athens, Greece -

Athens is one of the few ancient cities still active today. One of the world's oldest cities, with its recorded history spanning over 3,400 years, Athens' population peaked in antiquity at approximately 155,000 in 430 BCE.

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Datong, China -

At its peak, Datong numbered a population of around 200,000. The city was called Taitong or Tatung in ancient times and rose to prominence after the Wei dynasty gained control of northern China and established Datong as the capital in 398 CE. Datong's ancient remains contrast starkly with the present-day city, which borders Inner Mongolia to the north and west and China's Hebei province to the east.

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Anuradhapura, Sri Lanka -

Anuradhapura was founded in 437 BCE, though the site had been inhabited for much longer, in fact for almost three millennia. Famous for its well-preserved ruins of the ancient Sinhalese civilization, Anuradhapura was a major intellectual center for early Theravada Buddhism, and by 100 CE numbered around 200,000 people.

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Pergamum, Turkey -

Pergamum, located in present-day Turkey, was a rich and powerful ancient Greek city set on a hill on the north side of the Caicus River. As one of the major cultural centers of the Greek world, Pergamum reached its peak in the Hellenistic era in the 4th century BCE when its population swelled to 200,000.

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Vaishali, India -

Ancient Vaishali contains one of the best-preserved of the Pillars of Ashoka, a series of monolithic columns dispersed throughout the Indian subcontinent. An important location in the history of Buddhism (Buddha was a frequent visitor of the city), Vaishali thrived between the 6th and 5th centuries BCE, with its population numbering 200,000 during this period.

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Babylon, Iraq -

Legendary Babylon was one of the most important urban centers of the ancient Near East, and is considered the birthplace of Western urbanization. Babylon functioned as the main cultural and political hub of the Akkadian-speaking region of Babylonia, and its population was as high as 200,000 in 600 BCE.

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Merv, Turkmenistan -

Set in the remote Karakum Desert in Turkmenistan near the modern-day city of Mary, Merv was a major center of Islamic science and culture and by 1150 CE was arguably the largest city in the world, with as many as 200,000 living and working within its walls.

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Capua, Italy -

Capua exists today as a popular travel destination in the region of Campania, southern Italy. In antiquity the city was one of the wealthiest and largest of the Roman Empire. Indeed, many called it "the second Rome." Its peak population of 240,000 was recorded in 200 CE.

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Pataliputra, India -

Very little of ancient Pataliputra has been excavated. Most of it still lies buried beneath modern Patna. But in 300 BCE this was a major city of 400,000. It's one of the oldest city sites in India, having been founded in 490 BCE.

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Ctesiphon, Iraq -

In 600 CE, Ctesiphon was the second-largest city in the world, its population edging towards 500,000. Ancient Ctesiphon served as a royal capital of the Iranian empires for over 800 years, and was the grand capital of the Sasanian Empire from 226–637 CE until the Muslim conquest of Persia in 651.

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Nanjing, China -

Modern Nanjing has a population today of just under 9,948,000. In 500 CE, it was one of the world's largest cities, numbering 500,000. It has remained one of China's most important cities for over a thousand years and is recognized as one of the Four Great Ancient Capitals of China.

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Carthage, Tunisia -

Carthage was one of the most affluent cities of the classical world, its wealth generated by its status as an important Mediterranean trading hub. Carthage is said to have had 500,000 people around 300 BCE, during the Roman Empire.

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Constantinople, Turkey -

Constantinople became the capital of the Roman Empire during the reign of Constantine the Great in 330 CE. By 600 CE, its population had swelled to 600,000. The city was renamed Istanbul in 1930.

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Alexandria, Egypt -

At its height in 100 BCE, Alexandria boasted a population of one million. Founded by Alexander the Great, it was for a time the largest city in the ancient world before being eventually overtaken by Rome.

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Rome, Italy -

The most important city in antiquity was also the most populous. The center of the ancient world's greatest empire, Rome numbered a population of 1.2 million at the height of its power.

Sources: (UNESCO) (Britannica) (History) (Macrotrends) (United Nations) 

See also: Modern cities built on ancient ruins

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