Michamvi Peninsula, east coast
Halfway between the villages of Pingwe and Dongwe on the Michamvi Peninsula, a shallow pocket of reef flat fills with impossibly turquoise water that locals and tour operators simply call the Blue Lagoon. It's one of the most popular snorkel stops on Zanzibar's east coast, with seagrass beds drawing clownfish, surgeonfish and butterflyfish, usually paired on a half-day trip with lunch at the world-famous Rock Restaurant just around the point.