Kigali Rwanda's highest buildings, including the 20-storey Kigali City Tower, are located in the CBD, as are the headquarters of the country's largest banks and businesses. Other buildings in the CBD include the upmarket Serena, Marriott and Mille Collines hotels, the University Teaching Hospital of Kigali, the national university's College of Science and Technology, and government buildings such as the National Bank of Rwanda and the Ministry of Finance and Economic Planning. To the south west of the CBD, and also on the Nyarugenge Hill, is the suburb of Nyamirambo. This was the second part of the city to be settled,
Kigali three administrative districts—Nyarugenge, which lies in the south west, Kicukiro in the south east, and Gasabo, which occupies the northern half of the city's territory. Kigali lies in a region of rolling hills, with a series of valleys and ridges joined by steep slopes. Kigali lies between the two mountains of Mount Kigali and Mount Jali, both of which have altitudes over , while the lowest areas of the city have an altitude of . Geologically, the city lies in a granitic and metasedimentary region, with lateritic soils on the hills and alluvial soils in the valleys. The Nyabarongo River,