From the wildlife rich waterways of Tortuguero to the dense jungle coastline of the Osa Peninsula, an area labelled by National Geographic as 'the most biologically intense place on Earth', Costa Rica reveals its secrets: Scarlet macaws rule the roost adding brilliant flashes of red, blue and gold to the foliage; Humpback whales breed in the waters off-shore, and sloths lazily crawl along cecropia branches.