Why buy apartment for sale in Ongata Rongai? Ongata Rongai, sometimes referred to as Rongai or Ronga, is a town in Kajiado county that is situated in the southern part of Nairobi and West of the Ngong Hills. To serve the needs of the expanding population in the town, Rongai is home to a number of reputable banks, hotels, schools, and shopping centers. Some of the estates in Rongai include Nkoroi, Tuala, Rangau, Rimpa and more.