Having been declared nature sanctuary years ago, Round Island and Serpent Island are situated rather far out in the Ocean and out of bounds for regular visitors. Being so remote, their fauna and flora is a veritable treasure trove for botanists and zoologists; featuring a rare boa on Round Island and the only native tarantula to the Mascarenes on Serpent Island. It is unknown how they got there, as there are no such species on all other islands, but theories of continental drifts have been raised by scientists.