1. points to consider
1.1. Hot Climate
1.2. Adventure
1.3. coastal/mountain/safari holiday
1.4. travel time doesn't matter
1.5. wild life
1.6. likes exploring
1.7. architecture
1.8. exotic food
2. Mafia island
2.1. Adventurous activities
2.1.1. Mafia island scuba diving
2.1.1.1. Mafia island scuba diving is a very popular type of activity that can be done there. Reviews from other tourists that did it all say it was a wonderful experience, and it only has positive reviews. It is a 5 star activity. Here is what the website of Mafia island diving says: "Mafia Island Diving is Mafia Island's leading dive centre and the only one officially rated PADI 5 stars. It is run by a PADI Master Instructor and a PADI MSDT. We make a point for all our dive guides to be at least Divmasters. We offer the widest range of water and land based activities. Our dive sites are suitable for both beginners and advanced certified divers. We also offer PADI's full range of courses, from Discover Diving to Assistant Instructor and 15 different specialities. Divers and non-divers alike can also enjoy snorkelling, whale sharks excursions, whale watching, turtle hatching, birdwatching, island tours & picnics, jeep tours and much more."
2.1.2. Whale sharks watching
2.1.2.1. http://mafiaisland.com/en/diving-2/whale-sharks-watching-in-mafia-island/
2.2. Hotels
2.2.1. Chole Mjini can be a perfect place to get away: a quiet and unspoilt spot, yet quite social – with a fantastic community atmosphere. It is a high-quality lodge, although it has deliberately chosen to avoid many of the mod cons that we take for granted – and we think it's all the better for it!
2.2.2. 3 night stay with 2 days in November, $613 (USD) for the three nights in a tree house challet with all meals included
2.3. Mnjini is a really esoteric and interesting island you can do swimming, snorkling, scuba diving with the fish such as wale sharks and others fish species. you can also look at turtle haching. you can live in a tree house too!
3. Dar es Salaam
3.1. Hotel
3.1.1. There is a hotel in Das es Salaam, near the airport, that is called Transit Motel Airport, and it is 3 1/2 stars. It costs 47CHF per night, and it is very convenient since it is very near to the airport.