In about 750 CE, the Mayan city of Tikal had a population of more than 60,000 souls. During its peak, archaeologists believe that the city center spanned almost six square miles, and further research tells us that Tikal's population may have spread outwards from the center for at least 47 square miles.
The city remained a secret for more than a thousand years; Spanish conquistadores passed within a few miles of Tikal on their rapacious journey through the area, but never learned of its existence. In 1848, the Guatemalan government made the first official expedition and report on the city; it was declared a National Park in 1995. Today, modern Mayans celebrate their ancestors with pilgrimages to Tikal, which hosts more than 100,000 Guatemalan visitors each year.
Much of Tikal is still unexcavated, but you can see its Grand Plaza, Acropolis, pyramids, and temples on Smithsonian Journeys' Guatemala: Land of Eternal Spring tour in 2010.
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