チンギス・ハンと郵便システム
Genghis Khan, the founder of the Mongol Empire, created an amazing postal system called "Yam." This system used horse riders who changed horses at stations placed every 40 km. It allowed messages to travel quickly across the vast empire. Thanks to Yam, the Mongol army could receive orders fast and rule their lands effectively. This system was an early version of modern postal and communication networks.
