Hogan (a traditional dwelling of the Navajo people) at Canyon De Chelly in Arizona. Today, while some older hogans are now still used as dwellings and others are maintained for ceremonial purposes, new hogans are rarely intended as family dwellings. Traditional structured hogans are also considered pioneers of energy efficient homes. Using packed mud against the entire wood structure, the home was kept cool by natural air ventilation and water sprinkled on the dirt ground inside. During the winter, the fireplace kept the inside warm for a long period of time and well into the night.