Sumatra Stone Stories offers ethical, small-group orangutan trekking tours from Bukit Lawang, the gateway village to Gunung Leuser National Park — one of the last places on Earth to see wild Sumatran orangutans in their natural habitat. Led by licensed local guides, treks range from a half-day jungle walk to a 5-day rainforest expedition, all following strict no-touch, no-feeding wildlife guidelines. Packages include park permits, meals, and the classic river tubing ride back to the village. https://treksumatraorangutan.com/