Nairobi ni ndogo but iko well connected with its metro regions, some people along thika road think they live in Nairobi when they actually live in Kiambu county, some others along mombasa road (where there are plenty of factories ,bluechip companies, telco companies,go downs, gated villas) think they are in Nairobi kumbe they are actualy in machakos county......... Konza city will also be another metro city on the south of nairobi, tatu city on the west pia.......... in short what am saying is Dar may have lots of space for future expansion but nairobi has alot of fast rising satelite towns that are well connected to the CBD especially with all the bypass and ring roads that have been constructed... Did you know that interms of GDP/capita Kajiado(borders nairobi)Kiambu (borders nairobi) are richer than Nairobi? ...So I dont know why mnashobokea eti sijui dar na nairobi...blah blah bla...gues what nairobi is small but its the only capital city with a national park covering 113 sq/km.... tena tuko na recreational facilities all over the city like uhuru park jivanjee gardens and the likes.... thats enough evidence to show we can probably live in a smaller space if we plan better....... ... as of right now nairobi is not well areanged and urban planned like other cities in the world but its definately better planned than dar, if you plan better, dar residents could probably fit in a quarter of the space in dar.... its probably going to be a very long time before we both run out of space