Here I was watching Return of the King and thinking how cool the Gondor Beacons were (imagine the Appalachians with a similar system where New York calls out for help from Georgia) when I found out that this system was actually used in China in the Valley of a Hundred Fengsui:

If you’ve seen The Lord of the Rings: Return of the King and remember the scene where Pippin sets a large tower alight, sending a message calling for help across an entire mountain range, you know how the system of fengsui worked. All along the wall, from Jiayuguan to Shanhaiguan, beacon towers were built so that a fire signal (feng) or smoke signal (sui) sent from one would be visible from the next in line, making it possible to transmit military information back and forth rapidly across the entire border region. According to one military manual from the Tang Dynasty (618-907 AD), when the system worked according to plan a message could travel 1000 kilometres in a day and a night.