It is a westerly state, with hot, humid climate and swampy lowland lying at an altitude of 450m. Baro River and its tributaries, which flow to the Blue Nile, largely dominate Gambella. Gambella has two main ethnic groups, the Agnuak and the Nuer. The Agnuak speak a language close to the Luo in Kenya and they are tall and dark skinned. Traditionally the Agnuak are fishermen and agriculturalists. The Nuer who are taller and dark skinned are thought to originate from Nilotic parts of Sudan. The Gambellas have strong historic, ethnic and climatic links with the neighboring Sudan. The main tourist attraction to be mentioned in the region is the Gambella National Park.