Arusha is in northern Tanzania, at the foot of Mount Meru. It is the main hub of the region, and the main base from which northern Tanzania safari operators work. It is about an hour from Kilimanjaro International Airport.
Arusha is a rapidly growing city, but one that which, in the centre, retains the feeling of quite a small accessible town. Its skyline is still low rise, and jacaranda trees line many of the streets.
The famous (yet fairly uninspiring!) Clock Tower is half way between Cape Town and Cairo. Arusha's other claim to fame is that this is where Hatari! was filmed with John Wayne in 1962.
Just outside of the town is Arusha National Park, which is certainly worth visiting.
Arusha has a domestic airport from which internal airlines have scheduled flights to many other destinations in Tanzania, and which is used by charter planes.