but any city along the coastline inclding dar or even mombasa or durban are all at sealevel and hence < or = 50m. hautaniambia eti dar iko chini zaidi ilhali iko at sea-level.! the only place i knw tht's below the sealevel is a place somewhere in egypt. (jina nimesahau). so hautanishawishi eti JNIA iko special zaidi kuliko viwanja vingine ambavyo vimo kwenye ufuo wa bahari vilevile..
a point of correction:-
in physics class i remember, "the higher you go the lower the pressure".. same case "the higher you go the thinner the air" ie. their's more oxygen at sealevel than in the highlands like arusha for instance. so hio hoja yako eti "the higher you go the denser the pressure or air" hio ninapinga kabisa kabisa!...