A 353-hectare reserve extending a kilometre out to sea, Blue Bay Marine Park has the best preserved underwater scenery on the island, with a strong current which keeps it pristine and translucent. Around forty different species of coral – some up to eight hundred years old – have been identified here, including one of the largest brain corals in the Indian Ocean measuring 5.5m in diameter. The seventy or so species of tropical fish, meanwhile, include seahorses, surgeon, parrot fish, trumpet fish and butterfly fish, along with turtles and moray eels. Designated a Ramsar site in 2008, the park is only accessible only by glass-bottom boat. For more information contact Mauritius Marine Conservation Society (MMCS; w mmcs-ngo.org) and Reef Conservation Mauritius (w reefconservation.mu).