Palm oil plantations are a major contributor to the economy of Sabah and are spread all over Sabah. In fact large tracts of virgin rainforest have been cleared to make place for palm oil plantations. The Gomantong caves lie along the road to Sukau in the lower Kinabatangan area in Sabah. They are large limestone caves, of which the larger one, Simud Hitam, has the largest pile of guano (bat excrements) in the world. The Bavanggazo Rungus longhouse is located 41 km south of Kudat and 98km north of Kota Kinabalu. It is a big, very well preserved longhouse built with traditional materials.