Sri Lanka’s last viable primary tropical rainforest is a UNESCO World Heritage Site and one of the most biodiverse patches of forest on the planet – over 60 percent of its trees are endemic, and the wildlife that lives among them includes dozens of species found nowhere else on earth. Walking through Sinharaja with a local naturalist guide is a different kind of experience from any national park safari – quieter, slower, more intimate, and full of the kind of small, revelatory encounters (a rare frog on a leaf, a mixed-species bird flock moving through the canopy) that make genuinely committed nature travellers feel very lucky indeed.