Heunginjimun Gate (Dongdaemun)

This guide to Heunginjimun Gate (Dongdaemun) in Seoul opens in 1907, as workmen tear down the curved outer wall that had once made this gate unlike any other in Seoul's fortifications. It goes back to 1398, when King Taejo's builders realized this gate sat on unusually low, exposed ground, and traces the horseshoe-shaped defense they built to compensate. Look closely at the base of the gate for traces of where that vanished outer wall once wrapped around it.