The fully protected Chumbe Reef Sanctuary is the first marine park of Tanzania, one of the world's most beautiful coral gardens and the best-preserved shallow reef on the East African Coast. The sanctuary has more than 200 species of pristine corals (about 90% of all species recorded in the region), more than 400 species of fish and regularly visiting turtles and dolphins. This spectacular reef can be observed by snorkelling under the guidance of trained park rangers.

Snorkelling lessons where needed and equipment are provided on the island. Scuba diving to neighbouring reefs can be arranged upon request.

The Chumbe Forest Reserve has a unique flora and wildlife including numerous reptiles, birds, crabs and the awe-inspiring rare nocturnal coconut crab (Birgus latro), the largest land crab on earth. Forest Nature Trails can be visited under the guidance of trained park rangers.

The island is formed from fossilised coral and throughout the trail it is possible to see the patterns of the coral and the remains of giant clams thousands of years old. Chumbe is also a breeding sanctuary for the endemic Aders's duiker (Cephalophus adersi), the rarest antelope on earth that is threatened by extinction in Zanzibar.