Water Route: San Juan River
We begin our journey visiting the Solentiname Archipielago in Lake Cocibolca, famous as an artist's colony, and then you will visit Los Guatuzos, a wildlife refuge. As you go down the waters of the beautiful San Juan River, you will get to the Castle of the Immaculate Conception, a bulwark of defense against English pirates in the last half of the 18th century.
Solentiname
Solentiname's archipelago is located in the south part of the Nicaragua Big Lake (Cocibolca) and has 36 islands of varying size. The archipelago is part of the Nicaraguan depression formed in the Tertiary period (26-66 million years ago). Its elevation is between 100 to 780 ft. (30 to 250 m)above sea level.
Limitated turist access and a short supply of electricity make these islands are an ideal quite place to get away from all. Solentiname is in the tropical zone and also has a dry season. Rainfall averages 1,500 mm (59 in.) from May to December and average temperature is 26-28 C (79-84 F).
Most of Solentiname is covered by young or regrowth trees. Macarroncito island has only old growth. The archipelago's economic activity is based on agriculture and cattle raising.
The number of fauna and flora species is smaller here than in other San Juan's department side, but Solentiname has several unusual species, mainly amphibian, that are difficult to find in other areas. The archipelago has many archeological sites where you can see pre-colombian sculptures and caves with old paintings and drawings.
San Juan River
The river starts at the southwest corner of the Lake Nicaragua (San Carlos town), and flows for 119 miles (199 km) to the Caribbean Ocean (Greytown). It is the natural border with Costa Rica. The whole area is considered a tropical rain forest. The bio diversity is spectacular. All along the river you will see hundreds of different bird species like: Chestnut Toucans, Harpy Eagles, Boat-billed herons, Great Egrets, Jacanas and Cormorants. Other species as caimans (crocodile), turtles, monkeys, red arrow frogs.
The city of San Carlos about 190 miles southeast of Managua, is the lake port gateway to the area. Lake Nicaragua (covering 5,067 square miles) is one of the largest freshwater lakes in the world. It is no local legend that the lake is home to sharks, sawfish and other saltwater species. They swim from the Caribbean, up the San Juan River and return.
The area just south of the Archipelago, and on the Nicaraguan side of the border with Costa Rica, is known as Los Guatuzos, a nature reserve to make the most experienced naturalist's eyes bulge. Birds, reptiles, and mammals of almost every description live and frolic in the exuberant foliage. Boat trips through the Solentiname islands and the preserves can be obtained in San Carlos.
Traveling down the San Juan River, in the direction of the Caribbean is spectacular. Your first major stop is Castillo La Inmaculada Concepción where the ruins of an old Spanish fort stand on a hill guarding the river communities from Caribbean pirates. It was here in 1780 that Horatio Nelson, then a young captain, met defeat in an attempt to capture Granada and Leon, to assure the British a route between the Atlantic and Pacific.
The Río San Juan is a special area where nature reserves have been established, and strong conservation measures are taken, to keep civilization from intruding on the natural wonders of the area. It is now possible to take a boat from San Carlos all the way to the mouth of the Río San Juan at San Juan del Norte. San Juan del Norte (originally known as Greytown) is the Caribbean delta terminus of the San Juan River.
There is immediate access to Costa Rica via Los Chiles, (20 minutes ride) from San Carlos through the Frio river. From here there is an excellent highway to San Jose (5 to 6 hours). This enables any combination of tours starting in Costa Rica, continuing to Nicaragua or vice versa. San Carlos is an international entry point for Nicaragua, if you enter or exit Nicaragua through this town, normal immigration and customs procedures and costs will apply.