Rio San Juan
This department could best be described as the outback of Nicaragua. With virtually no roads, transport tends to be by foot or river. In fact, the Rio San Juan is the second longest river in Central America.
If you are looking for howler monkeys, exotic birds and jungle, this is the place to visit. The river itself is 190km long and up to 350m wide. It drops at a rate of 18cm/km from Lake Nicaragua to the Caribbean. The region includes the 362,000 hectare Indio-Maí Biological Reserve, the second largest in Central America.
One important point about the river is that it is Nicaraguan. That is, the entire river is within the territory of Nicaragua. While this has always been the case, there have been numerous disputes with Costa Rica over the use of the river for commercial transport.