The sweat lodge (purification ceremony, sweat house, medicine lodge, medicine house) is a ceremonial sauna and an important event in Native American cultures. There are several styles of sweat lodges that include a domed or oblong hut similar to a wickiup, or even a simple hole dug into the ground and covered with planks or tree trunks. Stones are heated in an exterior fire and then placed in a central pit in the ground. In this photograph taken by Edward Curtis, in 1905, three Navajo men, seated, watching over a man covered with a blanket anchored by sticks with feathers attached. Rather than heated rocks the scorching desert sun and the wool of the blanket are used to make the "sweat".