How did beacon fires on hilltops guide ancient sailors?

Before the development of formal lighthouses, ancient sailors relied on beacon fires kindled on hilltops to assist with coastal navigation. These fires served as early precursors to modern lighthouses, providing a visual reference point for mariners to establish their position and guide them toward their destinations or safe harbor approaches.12

These primitive aids consisted of wood fires or torches burned in the open, sometimes shielded by a roof to protect the flame. While simple, these fires were essential for maritime safety, offering a reliable, albeit basic, method for sailors to identify the coastline and avoid hazards during the night. The earliest literary references to these hilltop beacons are found in the Iliad and the Odyssey, dating back to the 8th century BCE. Over time, these methods evolved into more sophisticated structures, eventually incorporating lanterns with oil lamps or candles protected by glass or horn.1