Western Circuit
The Western Circuit embraces the parks along Lake Tanganyika, the western border of Tanzania with the Democratic Republic of Congo (DRC). The vast space in a remote natural location makes the circuit worth a visit.
Gombe Stream National Park was made famous by Jane Goodall’s research on its chimpanzee population and subsequent habituation. Mahale Mountains National Park further south, on the shores of the gin-clear waters of Lake Tanganyika, is a more authentic chimpanzee experience and highly recommended.
You'll have to go further to find the chimps but you'll get a better idea of how chimps are in the wild than by observing them at feeding pens. Katavi National Park is another 150km towards the south-east of Mahale and probably gets fewer than 500 tourists a year.