The last remaining primary lowland rainforest in Sri Lanka and a UNESCO Natural World Heritage Site, Sinharaja holds 21 of the island’s 26 endemic bird species and a density of endemic flora and fauna almost without parallel in South Asia. The mixed-species feeding flocks that move through the canopy throughout the day create a birdwatching experience that specialists rate among the finest available anywhere in the world. A guided walk with a Sinharaja naturalist is not a forest walk with interesting birds. It is an immersion in a biological system of extraordinary complexity.