The city is built in hilly country, sprawling across about
four ridges and the valleys in between. The city centre is located on one of
these ridges, with the main government area on another. The tops of the ridges
have an average elevation of 1,600 metres (5,250 ft), while the
valleys are around 1,300 m (4,270 ft). The bigger houses and office
buildings tend to be on the tops of the ridges, while the poorer people live in
the valleys. The city is ringed most of the way round by higher hills, with
some suburban sprawl rising up these. The highest of these is Mt. Kigali, with
an elevation of
