Maru, on the other hand, is a traditional Korean cooling system and refers to the board-floored room at the center of a hanok. It’s usually raised off of the ground to allow air to circulate beneath it, allowing the maru to stay cool during hot weather. Naturally, you don’t want to build a house with wooden floors and then use fire to heat said floors, so the hanok is carefully designed to incorporate both ondol and maru to adapt to South Korea’s cold, dry winters and hot, humid summers.
