Lost cities

Angkor, cambodia
Angkor was once the largest city in the world and more than a million people lived there. The city had an area of more than 78 sq km and was surrounded by a water-filled moat. It was abandoned in about AD 1100. French naturalist Henri Mouhot was the first westerner to discover the city, in 1861.

Atlantis
Some people believe that there was a city and island of Atlantis, perhaps in the Mediterranean, that was destroyed by an earthquake and flooding almost 12,000 years ago. No one knows exactly where it was or even whether it really existed.

Chicten itza, Mexico
Chicten itza was once the centre of the Mayan empire. It was built in about AD 400 and had many buildings used in Mayan rituals. The city was abandoned in AD 1200.

Cliff Palace (Mesa Verde), Colorado, USA
This Native American Indian city was built on a cliff side, but was abandoned during a long drought in the late 13th century. It lay unknown until 18 December 1888, when Richard Wetherill, a local farmer, spotted it while looking or stray cattle.