Ptolemy made several significant contributions to the field of geography, the most notable of which include:

• Geocentric Model: Ptolemy's astronomical theories, particularly his geocentric model of the universe, greatly influenced Western thought for over a millennium. Although later proven incorrect by the heliocentric model proposed by Copernicus, Ptolemy's geocentric model provided a framework for understanding celestial movements and their effects on Earth.
• Coordinate System: Ptolemy introduced the concept of latitude and longitude, coordinates to geographical mapping. By dividing the Earth's surface into a grid system, he enabled precise location determination, which proved invaluable for navigation, exploration, and the creation of maps.
• Geographical Data Compilation: Ptolemy compiled extensive geographical data from various sources, including earlier Greek texts, travelers' accounts, and his own observations. He organized this information systematically in his works, providing detailed descriptions of regions, cities, rivers, and landmarks across the known world.
• Projection Methods: Ptolemy developed innovative projection methods for mapping the spherical Earth onto a flat surface. His projections, such as the conical projections, allowed for more accurate representations of geographical features and distances, laying the groundwork for modern cartography.
• Cartographic Works: Ptolemy's most influential contribution to geography is his magnum opus, "Geographia" (Geography), which presented a comprehensive atlas of the known world accompanied by detailed maps. This work not only served as a reference for scholars and explorers but also played a crucial role in shaping European perceptions of geography during the Middle Ages and Renaissance.