Traveling to Serengeti and Zanzibar after gorilla trekking in Bwindi, Uganda
If you plan to visit Serengeti national park in Tanzania and Zanzibar after gorilla trekking at Bwindi National Park in Uganda, you can fly out of Kigali Airport to Kilimanjaro airport. From Kilimanjaro airport, your tour operator will pick you up and drive to Serengeti or even Ngorongoro crater. Alternatively, fly from Bwindi National Park to Serengeti via Entebbe International Airport in Uganda.
When you have completed the safari in Serengeti, you can then fly to Zanzibar from Seronera Airstrip. There are currently no direct flights from Seronera to Zanzibar. You are very likely to get a connecting flight via Kilimanjaro airport. Alternatively, your tour operator can drop you off at Kilimanjaro airport and fly directly to Zanzibar. Precision Air runs a couple of direct flights from Kilimanjaro airport to Zanzibar every week. There are other flight options, as well.
There are two airports in Zanzibar: Abeid Amani Karume International Airport located in the Zanzibar Archipelago. This is the primary and only international airport in Zanzibar. The other small airport is called Pemba Airport, located in Pemba Island. You can fly from Kilimanjaro Airport direct to Abeid Amani Karume International Airport. You could also plan your flight out of Tanzania from Abeid Amani Karume International Airport via Dar Es Salaam, depending on which airport serves you better.