Ondol is a traditional Korean heating system that has been used for centuries. It works by circulating warm air from a fire or heating source through flues under the floor, warming the space above. This method not only heats the room but also provides a comfortable and cozy environment, especially during cold winters. The design of ondol allows for efficient heat retention, making it an energy-saving option. It is commonly found in traditional Korean homes and is often associated with the cultural practice of sitting on the floor. Today, modern versions of ondol continue to be popular in contemporary Korean architecture.