The capital of Zanzibar , located on the island of Unguja , is Zanzibar City . Of this , around two thirds of the people â `` 622,459 â `` live on Zanzibar Island ( Unguja ) , with the greatest proportion settled in the densely populated west . Zanzibar 's largest settlement is Zanzibar Town ( sometimes called Zanzibar City ) , on Zanzibar Island , with 205,870 inhabitants .