Hands up anyone who has ever heard of the Rio San Juan? Me either, but it is one of the most beautiful and tranquil places in Nicaragua and it boasts a history second to none.
Since the Aztecs first used the Rio San Juan in the 1200s to link their trade routes from east to west, the river has been a vital artery between the Pacific and the Caribbean. In the sixteenth, seventeenth and eighteenth centuries it was at the centre of a global battle between European nations vying for the treasures of the new world.
Throughout those centuries the river became the stuff of legend, incorporating Inca gold shipped to Spain by Conquistadors; pirates sneaking up the river to attack the fabulously wealthy Spanish colonial city of Granada; a teenage girl defending the fort at El Castillo against a flotilla of English ships; and the English navy, led by Horatio Nelson, attacking Spanish forts along the river before being driven back as his men died wholesale from malaria and dysentery.
In the nineteenth century the river was a global super-highway shuttling prospectors to the California Gold Rush (1848-55), making shipping magnet Cornelius Vanderbilt a very wealthy man. More than 150,000 people travelled up the Rio San Juan en route to San Francisco and the river was the scene of frenzied activity. At the rapids by the village of El Castillo a railway was constructed to help transfer passengers from one boat to another.
From the earliest days of the discovery of Nicaragua in 1502, the strategic and commercial importance of a waterway linking the Pacific and the Atlantic was understood. The Rio San Juan flows out of Lago Nicaragua, which is only a short distance from the Pacific ocean and could have been linked by a canal. Towards the end of the nineteenth and start of the twentieth centuries this almost became a reality but Panama got there first.
The dramas played out along this river are virtually unknown today, even though it continues to be a source of tension and occasional conflict between Nicaragua and Costa Rica. The river is entirely Nicaraguan, but just south of El Castillo it forms the border between the two countries and there is an ongoing dispute between them as to the right to use the river.
If there is a more historic and dramatic river in the Americas than Rio San Juan I don’t know where it is, yet the river is so much more than its history. It flows through a beautiful and timeless area of Nicaragua and links small, isolated but welcoming communities that are just now opening their doors to tourism. It is a truly wonderful region to visit.
As you travel down the river there is a stark contrast between the Nicaraguan side and the Costa Rican side. Along the Nicaraguan side lies a vast and pristine rain forest, the Reserva Biologica Indio-Maiz, that is home to an extraordinary catalogue of flora and fauna. The Costa Rican side is virtually deforested. In other words, a country known for its ecological policies has allowed a tropical rain forest to be destroyed. Luckily it can still be seen and visited on the Nicaraguan side.
Notes from Camelid Country 
I’m grateful that Nicaragua has maintained this beautiful area for locals and visitors alike. But who’s to say that they won’t soon allow it to be deforested as Costa Rica did? I wonder what we can do as tourists and visitors to help make sure that doesn’t happen, if anything.
Our guide told us that there was a government scheme, funded with assistance from Europe, to pay farmers not to encroach on the park boundaries. As is only too obvious in Brazil and Bolivia that this isn’t always effective, but if tourism to the reserva can provide an income for local communities there may be more of an incentive to preserve the forest.