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About how many places did Ptolemy record in his Guide to Geography?
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Ptolemy
Ptolemy's theory of the solar system.
In his monumental work, the Guide to Geography, Ptolemy recorded the longitudes and latitudes for roughly 8,000 locations.123
These coordinates, which were primarily derived from the writings and maps of earlier geographers like Marinus of Tyre, allowed for the creation of a detailed image of the world as it was known to residents of the Roman Empire at its height. While these locations provided a foundational framework for cartography, they were often based on approximate distances and directions from travelers rather than direct observation.23