Hi, in addition to the below I feel you may be confusing Zanzibar with Tanzania of which it is a part. Zanzibar is an old Arab trading island just off the coast of Tanzania and whilst it is home to some interesting animals, most notably the red colobus monkey, it isn't the location for a safari. What you can do is combine a safari on mainland Tanzania with a beach/relaxing holiday on Zanzibar. We did a long safari followed by a few days on Zanzibar organised by a wonderfully helpful company based in Tanzania called Duma Explorer, this is run by an American woman and her Tanzanian husband, they were able to tailor things to our exact needs and were excellent (I have no association with them other than as a very satisfied customer). As a male I would suggest that Stone Town (the capital of Zanzibar) might not be totally suitable for a single female traveller unless she were practised in fending off persistent street hawkers and the like but there are many other beautiful areas on the island to stay with possibly guided visits to the capital. I would strongly advise you to contact someone such as Duma for their 'on the ground' experience and advice. We shall most certainly be going back!