San Carlos is the embarkation point for boats to the splendor of the Solentiname Islands, Los Guatuzos Wildlife Reserve, and the majestic Río San Juan. However, San Carlos itself is not a place in which you want to spend any time. Make sure you arrive early in the day so you have time to make your connection and get out of town; there's not much to see here, and the choice of hotels is limited to two-bit flea joints.
When you arrive, you'll first see filthy, tin-topped shacks that run down the side of hill to a pleasant waterfront which overlooks the "Sweet Sea" (Lake Nicaragua) flowing into the grand Rio San Juan. San Carlos used to be one of Nicaragua's ugliest human settlements until it got something of a facelift along its waterfront, the malecon, in 2010. Relighting and repaving can do only so much, however, and sleazy hotels and rowdy bars still line its rougher streets, playing host to the multitude of transients that pass through on their way to somewhere else. Migrant workers, soldiers, ranchers, fishermen, and renegades all converge on what is the sultry, isolated capital of a sultry and isolated region. They are here because this ramshackle river town of 6,000 people is a major transportation hub, the gateway to the jungle of the east and Costa Rica to the south. It's also the end of the line for all buses that travel the grueling 9-hour trip from Managua on wet, rutted roads that would challenge a tank, never mind an ancient school bus with KENNEDY HIGH in faded lettering on the side.
San Carlos's superb location at the mouth of the Río San Juan that flows from Lago de Nicaragua to the Caribbean means it controls a waterway that almost connects two vast oceans. As Hernán Cortés told the Spanish king in 1524, "He who possesses the Río San Juan, possesses the world." San Carlos was thus founded in 1526, and a fort was built to guard the waterway and support the larger fort of El Castillo further downriver. Increased trade and its use as a changeover stop for Vanderbilt's gold-rush service meant the town took on the resemblance of 19th-century prosperity, with paved streets and colonial mansions. Trouble was never far off, however, be it from marauding pirates, William Walker's mercenaries, or bloody skirmishes with the local Guatuzo tribe, who were aggrieved that rubber tappers were encroaching on their land. Eventually, the settlers massacred the Indians or illegally traded them as slaves. The steamboat trade disappeared, the rubber price collapsed, and San Carlos' boom was over. Intermittent fighting between Somoza's National Guard and the Sandinistas in the 1970s was followed by a river war between the Sandinistas and the Contras in the 1980s.
Today, the only trouble is the occasional robbery or bar brawl, and diplomatic tiffs with Costa Rica to the south, which has always coveted the Río San Juan.
The Solentiname Archipelago
The Solentiname Archipelago is a scattering of 36 islands in the southern corner of Lago de Nicaragua. Geographically, it is an isolated, tropical backwater, but historically and culturally, it is the nucleus of Nicaragua's world-famous primitive art movement and a hotbed of liberation theology. That's due mainly to poet and priest Ernesto Cardenal, who came here in the late 1960s and encouraged ordinary islanders to pick up a paint brush and paint what they saw. The result was astounding -- vibrant renditions in oil and balsa wood of the islands' nature and people. Complete families became artists, and by the early 1970s TV crews were coming to make documentaries about the phenomenon. Only 750 people live on the islands today, but they act as hosts to hundreds of tourists every year who come to paint, observe, or study the region's rich natural wonders.
There are no roads, electricity, telephones, or running water. The islands may be just 2 hours away from the modern squalor of San Carlos, but they might as well be another world, abundant with pristine beauty and simple, primitive living. Dry shrub land runs into dense rainforest, punctuated by open meadows and avocado farms. There is ample wildlife with excellent fishing and bird-watching, as well as trekking and boating.