Zanzibar beaches are an hour's flight from the safari, and that proximity is the whole argument for going. You can watch lion at seven in the morning and be swimming before sunset. We book the flight as part of the trip so there is no backtracking to Arusha and nothing separate for you to arrange.

Where you stay matters more here than anywhere else in Tanzania, because the tides differ enormously around the island. The east coast has the reef and the better snorkelling but the water goes a long way out at low tide. The north, around Nungwi and Kendwa, is swimmable whatever the tide is doing. We ask which of those you actually care about before recommending anywhere.

Give Stone Town at least one night. It is a UNESCO World Heritage site and a working city rather than a preserved one, and the history in it — including the parts about the slave trade, which are neither comfortable nor optional — is worth a guided morning on foot before you go and lie on a beach.