“More than 150,000 people arrived from New York and passed through here,” said Misael Morales Sequeira, the town’s 34-year-old mayor. “The Gold Rush lasted 15 years, and it left no benefit for the town.”

History books note, though, that among the notables to pass by San Juan through the centuries were English privateer Francis Drake, Prussian explorer Alexander von Humboldt, writer Mark Twain, Italian Gen. Giuseppe Garibaldi and Robert E. Peary, who would go on to fame as the first explorer of the North Pole.

Remnants of San Juan’s heyday lie in rusty decrepitude in the lagoons and jungles. Still visible above water is the skeletal hulk of a sunken dredge and an iron-hulled steamship. Elsewhere, one sees rusted boilers and abandoned steam engines.

Wrought-iron fencing protects four cemeteries with headstones mostly in English. The cemeteries hold tombs of British and American sailors, Masons and Catholics.

A tragic period hit San Juan after the triumph of the 1979 Sandinista Revolution. U.S.-financed Contra rebels rose up (some under the leadership of Pastora), and both Sandinista and Contra fighters laced the area with landmines.

“The population of San Juan de Nicaragua decided to flee to Costa Rica,” Morales said. “They abandoned the town.” Most houses were burned to the ground.

When voters tossed the Sandinistas out of power in 1990, some 30 families returned, joining the single clan that had stayed. With United Nations help, the town was established on the banks of the Rio Indio about a mile and half from the original settlement. The name was subsequently changed from San Juan del Norte to San Juan de Nicaragua, although Greytown is still in common use.

Pastora was a crucial figure in a recent episode involving the region, perhaps fitting for a man whose personal history has oscillated like that of the port. Pastora, a onetime fisherman, became renowned as Commander Zero in the Sandinista uprising in the 1970s, only to turn on the Sandinistas in the 1980s as an armed foe. He returned to the Sandinista fold in recent years, rekindling a close friendship with Daniel Ortega. Through that back-and-forth, he found time to father 21 children with 10 women, four of whom he married.

“I know how to fish, to fight, to sin and to love,” he said.

In late 2010, while Pastora’s company dredged the San Juan River that demarcates the border, it ignited a dispute with Costa Rica, testing the neighbor’s sovereignty over an island in the delta, Isla Calero. The incident led to a buildup of Nicaraguan troops and police from Costa Rica, which has no standing army.

Eager to rally nationalist feelings ahead of elections in 2011, the Ortega government and the Sandinista Front set up outposts around and on the disputed island, defying requests from the Organization of American States to withdraw.

“This is 100 percent Nicaraguan soil. We must fight for every centimeter,” said Jose Luis Argenal, a Sandinista in charge of dozens of young men deployed to the island. Signs and graffiti on shacks described the island as worth dying for.

Both nations took the matter to the International Court of Justice in The Hague, and a verdict is expected in the spring of 2013. Yet to be seen is whether the decision will be accepted by both nations.

Pastora, meanwhile, earns $80,000 a month from the Ortega government for operating dredges along the San Juan River – a sum he considers insufficient.

“It is nothing,” Pastora said. “I’m asking for $200,000 a month.”

Pastora spoke in the dining room of the only hotel able to handle an inflow of tourists, the Rio Indio Lodge. At other tables were sports fishermen from Missouri, Washington state and Florida, eager to reel in the tarpon and snook abundant in local waters.

The lodge sits within the boundaries of the Indio Maiz Biological Reserve, an 850,000-acre preserve that is one of the largest untouched tracts in Central America.

“The intention of the government and our intention is that this becomes a world-class destination for birding, for nature,” said Alfredo Lopez, a physician who is the lodge’s chief executive. “The sport fishing is fabulous.”

Pastora, for his part, looked around the half-empty dining room and said a boom is in the offing.