The Río San Juan & Islas Solentiname

If you’re the type who likes islands draped in jungle, surrounded by crystalline waters that reflect the forest, sun and sky, and populated by farmers and fishers who share their wealth and also happen to be terrific artists and craftspeople, you do not want to miss this oft-overlooked archipelago. And we haven’t even mentioned the gators, monkeys, orchids and migratory waterfowl, the sensational offshore fishing, the mind-blowing sunsets and the spectacular starlight. Almost forgotten for 500 years, and nearly destroyed in a single day, the Archipiélago de Solentiname does not seem entirely of this world.

It sometimes feels that the thick jungle looming on the edges of Boca de Sábalos is about to reclaim this muddy, dusty town set at the confluence of the Ríos San Juan and Sábalos (Tarpon River). And therein lies its appeal. When you lounge on the terrace of your hotel, lodge or guesthouse at sunset, you’ll watch birds fish and ride end-of-the-day thermals as you hear that familiar, primordial roar of the howler monkeys in the distance.

Río Sábalos effectively splits the town in half, with the inexpensive hospedajes and main road on one side, and a smaller community, threaded by a slender footpath past rustic homes and gardens, on the other. It costs two córdobas (US$0.06) to cross the canal in the dugout canoe that goes back and forth.

Lined with brightly painted timber houses and crowned by a wonderfully evocative 17th-century Spanish fortress, it's no surprise that El Castillo is the Río San Juan's showpiece destination. It’s laced with pebbled-concrete walking paths that wind up, down and around the hill, shaded by mango, coconut, orange and almond trees, and fronted by a fast-flowing bend in the massive Río San Juan with two sets of rapids on it. A town this civilized means that the jungle has been tamed here, so don’t expect the howlers to sing you to sleep, though you're also just 15 minutes by boat from Nicaragua’s best-preserved lowland rainforest, the Reserva Biológica Indio-Maíz, making El Castillo an ideal base for numerous jungle adventures.

Nicaragua’s second-largest tract of intact primary forest, the 2606-sq-km Reserva Biológica Indio-Maíz, lies about 15 minutes downriver from El Castillo. Thanks to a combination of geographic isolation and inaccessibility, the reserve was spared the chainsaw under Somoza, and once the Sandinistas took power it was legislated as a reserve and has remained off-limits to tourists.

Tragically a devastating forest fire in April 2018 destroyed over 50 sq km of forest, in what has been termed Nicaragua's worst-ever environmental disaster. To add insult to injury, Costa Rica's attempt to send backup firefighters and equipment was rejected by the Nicaraguan government, the cause of great anger locally.

Today the vast majority of the reserve remains restricted, but it's possible to visit some small designated sections where you can hike among 50m-tall, 500-year-old cathedral trees, search for brightly colored tree frogs and watch monkeys leap through the canopy.

Most travelers miss this mellow lakeside fishing community and gateway to the region’s least-visited reserve, the Sistema de Humedales de San Miguelito or San Miguelito Wetlands. A handful of rivers meander through the reserve, including the Río Tepenaguazapa, the Río Camastro, the Río Tule and the gorgeous Río Piedra. Occasionally the grasslands and lotus fields teeming with birds and butterflies intervene. If you’re lucky, you may even see some alligators. This is your chance to easily get onto the path less beaten.

Dripping wet and laid-back, one of the Americas’ oldest European towns feels like it’s on the edge of the world. There are wide streets but no cars to fill them, and life is slow, even though the fishermen and boatbuilders work hard and want for little. How could they, in a town surrounded by rivers teeming with fish, virgin rainforest and jungle-fringed lagoons? They are cash poor, however, which leads to spotty electricity (carry a flashlight) and water service (shower when you can), and the locals dream of a tourism gold rush that, while theoretically possible, is unlikely to ever happen in this far-flung corner of Nicaragua. For now, however, it remains a dream destination for those comfortable on the edge.

Surging purposefully through rolling green hills, thick jungle and dense wetlands on its irrepressible march to the Caribbean, the Río San Juan forms much of Nicaragua's natural border with Costa Rica and is today a slowly developing traveler destination popular with those who enjoy wildlife-watching, hiking and kayaking. Once the domain of indigenous traders, Spanish conquistadors, British pirates, gold-hunting travelers and even Mark Twain, this river has history in bucketloads. Follow their example and penetrate the vine-hung wilderness of jaguars and macaws that is the Reserva Biológica Indio-Maíz, troll for tarpon, search for alligators in the moonlight and then make a toast to your adventures while overlooking the remains of a 16th-century Spanish fort. All of which will cost you. But it’s worth it to fully experience this spectacular and unforgettable waterway.

Like so many national treasures, Los Guatuzos wildlife reserve, a 440 sq km band of rich, river-streaked wilderness wedged between the Costa Rican border and Lago de Nicaragua, was conserved by accident. The earliest inhabitants, the Guatuzos, were sold into slavery and their lands co-opted by farmers whose crops (rubber and cacao) demanded shade. Just as foreign timber companies were poised to buy out the subsistence farmers, revolution and war hit hard along the border, and the various minefields left the region inaccessible and pristine. Declared mine-free in 2001, the area is now a wonderful side trip from San Carlos.