In 1380, near the end of the Goryeo dynasty, some 500 Japanese pirate (wako) ships lay anchored at Jinpo, the waters off present-day Gunsan. The Goryeo general Choi Museon arrived with a fleet of 100 ships equipped with cannon and fire-arrows of his own design and set the anchored pirate fleet ablaze — this became known as the Battle of Jinpo. It's widely considered the first naval battle in history fought with gunpowder weapons mounted on ships, predating the Battle of Lepanto (1571) — often cited in Western accounts as the first major gunpowder naval engagement — by roughly two centuries.
By ship count alone, the pirates outnumbered the Goryeo fleet nearly five to one. But the outcome was decisively one-sided: anchored and unable to maneuver, the pirate ships burned where they sat, in a battle that proved in practice that gunpowder weapons could overturn a numerical disadvantage. Today, Jinpo Maritime Theme Park displays monuments and a few decommissioned naval vessels commemorating the battle, and at a glance it can look like little more than a waterfront amusement park. But knowing that this stretch of water predates Europe's gunpowder naval history by two centuries changes how the display in front of you reads.