Río San Juan

The Río San Juan is the lake's only outlet, draining 200 kilometres east to the Caribbean. For three centuries the river was one of the most strategic waterways in the Americas: ships could come up the river, cross the lake and reach within twenty kilometres of the Pacific, making Nicaragua a natural place for the inter-oceanic canal that was eventually built across Panama instead.

The river is now mostly the preserve of boats, fishermen and the Indio-Maíz biological reserve on its southern bank. From San Carlos at the river's mouth on the lake you can ride a public lancha downstream to El Castillo — a sleepy village dominated by a colonial-era fortress — and continue all the way to the Caribbean if you have the time and the patience. The trip takes you through some of the best-preserved rainforest in Central America.

things to do sight
A story
In 1665 the English buccaneer Henry Morgan led a flotilla up the Río San Juan, crossed Lake Nicaragua and sacked Granada by surprise — the same route the Spanish had hoped to keep secret. The Spanish responded by building a series of stone forts along the river, the most spectacular of which is the Castillo de la Concepción at El Castillo. Joseph Conrad described the same forts decades later, having captained a steamer down the river himself.