Eco chic

Chumbe Island marine park: This luxury island resort is situated eight miles from Zanzibar and is the first privately managed Marine Park in the world. Uninhabited, it covers 24 hectares and contains a protected coral rag forest and reef. Snorkel through the unique shallow water Reef Sanctuary, explore the Forest Reserve or enjoy the historical monuments. Or just allow yourself a lazy day at the beach watching dhows and outrigger boats go by. Accommodation on the island is very special - it's what Robinson Crusoe could only have dreamt about!
From £100 per person per day depending on the season, more info here

Indonesia luxury beach resort: Immerse yourself in splendid isolation in the most unspoiled region of the Indonesian Archipelago. Tucked amongst the trees of this remote island are just seven luxury bungalows and three villas that offer complete solitude and comfort together with everything you need from an idyllic tropical setting. The property is 438 acres of dense tropical forest, with rice terraces and grasslands wrapped around the two-and-a-half-kilometre long beach. This world-class beach is protected on both ends by cliffs and headlands ensuring total exclusivity for guests.
Luxury bungalows & villas from US$350 to $950, more info here

Selous Game Reserve & Mafia Island holiday: This trip offers you the best of the awesome Selous Game Reserve (42,000 sq. km of wilderness) in Tanzania, and a slice of beach paradise that is the Mafia Archipelago. You'll spend time at the photogenic Selous Safari Camp, tucked away beside the beautiful Lake Nzelekela. The final five nights will be spent in the Mafia Archipelago - which consists of five sleepy tropical islands, clustered together in the Indian Ocean.
Tailormade from £2,303 (13 days) including flights, more info here