The Ulin Tree or Iron Tree (Eusideroxylon Zwageri) is one of the famous trees from the forests East Kalimantan (Borneo Island) with the characteristics of hard, strong, dark colored wood and resistance to sea water. This type of wood from the iron wood tree is not easly weathered, both in water and on land. This is the reason, this wood is widely used as a building material, especially for houses built on marshy land.