The Organization for Tropical Studies field station at La Selva in Sarapiqui is one of the premier rain forest research stations in the world.  Researchers have published thousands of scientific papers on tropical ecology based on their studies here.  La Selva teems with wildlife and you can easily see monkeys, toucans, parrots, sloths, agoutis, poison dart frogs, green iguanas, peccaries, morpho butterflies and many bird species.