The secret lies beneath the floor
On a cold day in a hanok, the traditional Korean house, the comfort may come not from a fireplace in the room but from the floor. The historic system called gudeul or ondol sends heat from a hearth through flues beneath stone floor slabs, then vents smoke through a chimney. The Academy of Korean Studies describes the hearth, underfloor passages, heated stones and chimney as parts of one system.
Two spaces, two seasonal solutions
Look for both an ondol room and a raised wooden maru hall. The ondol warms a room from below; the maru allows air to circulate beneath its boards. The Korean Cultural Center describes the combination as an adaptation to Korea's seasons. As you visit a hanok, notice changes in floor level and the transition between stone-warmed rooms and wooden platforms.
Traditional fire and modern hot water
Many modern Korean homes still use floor heating, but generally circulate warm water through pipes rather than sending the smoke and heat of a fire beneath stones. The concept continues, while the technology differs. Archaeological evidence for early forms spans different times and regions, so not every old Korean house had the same system.
Before a visit or hanok stay
Ask an operator about the actual heating system, access to the rooms, footwear rules, hours and reservations. Do not assume every historic house still has an active wood-fired ondol. This cultural guide does not confirm availability or amenities at any particular lodging.