Nungwi Beach
Kai Zanzibar Hotel and Spa
An adults-only four-star at the top of Nungwi's price range, about US$480 a night, built around a spa, a pool and a proper restaurant. Reviews are strong, 9.2/10 over 227 stays, so it's aimed at couples who want quiet and service rather than a party crowd. No kids, and you pay for the polish.