Zanzibar Coast (Tanzania, Zanzibar)

Beneath a coral cliff formed by the millennia-old accumulation of coral skeletons and shells , Zanzibar's pale sand meets a turquoise sea . These limestone formations are eroded by the tides and retain moisture, allowing trees like the casuarina (Casuarina equisetifolia) to anchor themselves. Native to the Asia-Pacific , this tree is used on tropical coasts to stabilize soils and break the sea wind . Here, its roots cling to the void above the ocean.