I have been to Tanzania twice and Zanzibar once. Zanzibar is a wonderful place, especially the Stone Town, a medieval stone village still used as the commercial center. Evidently Zanzibar is getting lots of tourists these days. Pemba has fewer hotels and no Stone Town. I imagine it would be sleepy and nice. Tanzania's economy was ruined by an experiment with "Ujamaa Socialism" and has not recovered. Das Es Salaam is a dump, but safer than Nairobi. The Tanzam Railway, built by the Chinese, would be an unusual trip. It goes through the Selous Game Reserve which is larger than new Jersey.