Geographia is a significant work by the ancient Greek geographer Ptolemy, written in the 2nd century AD. It serves as a comprehensive guide to the known world, detailing the geography, cartography, and cultural aspects of various regions. The text includes maps and descriptions of places, helping to standardize geographic knowledge in the ancient world. The work is divided into eight books, covering topics such as the Earth's shape, climate, and the locations of cities and regions. Geographia laid the foundation for modern geography and influenced explorers and cartographers throughout history, including during the Renaissance.