The Rio Platano Biosphere Reserve has become my favorite natural (and one of my favorite cultural) areas in all of Central America, surpassing that of more known countries, in particular Costa Rica.

The deep parts of the reserve are amazing untouched, and even where there are larger groups of indigenous people, there hasn't been too much deforestation. The wildlife was amazing (I saw 2 tapir, howler monkeys, spider monkeys, sloths, tree anteaters, white-faced monkeys, an ocelot, jaguarundi, crocodiles and caimans, several snakes and lizards, insects, and encountered several fresh jaguar tracks).

The indigenous culture (Miskito, Pech, and Garifuna) is also amazing. It's expensive to explore the reserve, but it's a priceless experience.