What to see on the Río San Juan: fortress, islands and nature
The region's major references are San Carlos, the historic fortress at El Castillo, the Solentiname archipelago and protected areas around Indio Maíz. These sites are spread across river and lake routes.
Main places to see
Explore San Carlos as a gateway and consider the fortress in El Castillo on a separate river journey. Solentiname offers another island context, while nature reserves require authorised routes and respect for conservation.
How to get around
Confirm each dock and boat route independently. The trip from San Carlos to El Castillo differs from travelling to Solentiname or a forest lodge farther downstream.
Before you travel
River conditions and protected-area restrictions matter as much as operating hours. Do not assume a single boat, guide or day trip can cover the entire region.