Keep an eye out for freshwater sharks, poetry-scribbling politicos and a colourful new species of eco-smart hotel in the Central American country.

There are places where rivers flood the imagination. In the tropics, they arc across continents, they wind towards hearts of darkness, they arrive at the sea in mile-wide deltas of dazzling brightness. TS Eliot called them strong brown gods, overflowing into legend. In Nicaragua, the Río San Juan is not so much a river as a national character – treacherous, beloved, iconic – snaking deep into the country. There was a time when the San Juan was quite the thoroughfare, an important Central American artery, heaving with pirates and adventurers eager to make a name for themselves. The river was the route to Granada, one of the grand cities of the Spanish Main. Its mansions were said to be stuffed with gold.

Lord Nelson conquered the river as a callow youth of 22; it was only a bad case of diarrhoea that forced his retreat downriver. Sir Francis Drake was here, flaunting his codpiece, as was the fearsome l’Olonnais, the French pirate famous for drinking Spanish blood. Henry Morgan, the kind of swashbuckling killer so beloved of seven-year-old boys, came up this river three times on his way to the honey pot of Granada. They built the fortress at El Castillo to ensure he didn’t make it a fourth.

These days things have gone rather quiet on the river: a few fishermen’s dugouts, the odd motorboat crossing between the banks, a ramshackle river-bus heading upstream. But there are still travellers on the San Juan, like me, bound for Granada, entranced by tropical waters and sleepy river towns and stories of Henry Morgan, and still able to break the journey at El Castillo, where the 19-year-old Rafaela Herrera once fought off a bunch of English pirates in her nightdress.

In about 200km of river between the Mosquito Coast on the Caribbean and Lake Nicaragua, El Castillo is the only place you’ll find a cold beer, a restaurant menu and an air-conditioned room. I made landfall in the early evening. Framed by rose-coloured river light, a cluster of wooden houses, weathered as prairie barns, stood on the right bank above cormorants drying their wings. There are no cars here. Everything comes and goes by the river, sacks of rice, crates of beer, outboard motors, strangers.

Pedro was the first person I met, the barman in a wide wooden room just above the Raudal del Diablo, the Devil’s Rapids. I was impressed that he could serve me a beer without stirring from his hammock. Mangrove swallows were diving on the darkening water. Pedro was dreaming of Granada. On the San Juan, people dream of Granada the way kids in Kansas dream of New York or Los Angeles. Pedro talked of,,,, (continue Reading at: http://www.cntraveller.com/gallery/nicaragua-central-america-hotel-guide )