As any historian of medieval East Asia or player of Civilization V: Brave New World will tell you, 15th century Koreans were really, really, really good at science.

A statue of King Sejong the Great in Seoul. Thanks, guy! Photo by Republic of Korea/Flickr.

Under the judicious rule of Sejong the Great, the kingdom's top researchers spent a lot of time looking at space and making maps of it.

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Heroes