This hard-to-reach park sits at the confluence of the Marañón and Ucayali rivers. The reserve is Peru's largest, encompassing more than 20,000 square km (7,722 square mi)—which makes it about the size of El Salvador. The landscape is diverse (picture seasonally flooded forests, oxbow lakes, and vast expanses of lowland rain forest). So are the animals who inhabit it, including pink river dolphins, black caimans, various kinds of monkeys, and more than 500 bird species.
As with many South American reserves, there are people living in Pacaya Samiria, around 40,000 according to recent estimates. Park rangers try to balance the needs of these local communities with efforts to protect the environment, and request a minimal S/120 entrance fee to help pay for that work. The park can only be reached by boat, but lies relatively close to the port of Nauta, 100 km (60 mi) south of Iquitos by road.