Ptolemy's Geography is a significant work by the ancient Greek geographer Claudius Ptolemy, written in the 2nd century CE. It compiles knowledge of the world at that time, including maps and descriptions of various regions. Ptolemy introduced a coordinate system using latitude and longitude, which greatly influenced future cartography. The text includes detailed information about over 8,000 places, providing insights into the geography of Europe, Asia, and North Africa. Ptolemy's Geography served as a foundational reference for explorers and mapmakers during the Middle Ages and the Renaissance, shaping the understanding of the world for centuries.