While other materials are occasionally used, clear Western Red cedar is by far the most popular, most attractive and most durable. Cedar has a mild, pleasant fragrance that many people associate with saunas. Western Red cedar's particular properties allow it to expand and contract. And the natural tannins make cedar rot resistant. This is important in a sauna where the wood is exposed to extremely high, dry temperatures, interspersed with blasts of humidity when water is splashed on the heater or the walls.