SAN JUAN, Nicaragua -- Boom and bust cycles are no stranger to this small town, which once played an outsized role in distant affairs.

Set in a protected harbor in Nicaragua’s remote southeast corner, the town in the mid-19th century was briefly the most important port in Central America. Tens of thousands of Americans with gold fever passed by its wharf.

Then a bust hit. Tropical jungle thick with jaguar and peccary overtook the town as civil war gripped Nicaragua. Three decades ago, just one family remained.

Now San Juan may be on the cusp of another boom.

The government is putting the finishing touches on a 4,900-foot runway and airport valued at $12 million, part of a race to develop the region as it maneuvers with neighboring Costa Rica over a disputed border. Shimmering mirage-like is an even greater yearning: Nicaragua again talks of building an inter-oceanic waterway to compete with the Panama Canal, with one terminus here.

The waterway would allow ships to transit from the Atlantic up the San Juan River to Lake Nicaragua, then across an 11-mile isthmus to the Pacific Ocean, or vice versa.

Even if the waterway remains an illusion — skeptics abound — the 1,800 people who now reside in San Juan voice gratitude for the renewed attention. Less than half a decade ago, boats provided the only access to the town. A single telephone was the lifeline to the outside world. Electricity flickered on and off.

Now there is reliable power and blanket cellular telephone service. The airport has cut the journey to the rest of Nicaragua and opened the doors to tourists, who come for sport fishing, bird watching and rousting around historic ruins.

“This corner of Nicaragua is a treasure trove,” said Eden Pastora, a onetime guerrilla commander who is the region’s biggest promoter.

President Daniel Ortega, head of the leftist Sandinista Front, appointed Pastora to head a commission seeking global financing for the $30 billion inter-oceanic waterway. Pastora, for his part, is delving into all manner of private development, including plans to build an international marina with scores of slips.

San Juan lies below the Caribbean hurricane belt, offering a safe harbor for yachts seeking shelter or long-term harborage.

Pastora, a fit-looking 75-year-old with a shock of white hair, said the airport, which is operational but so new that it has yet to be inaugurated, would facilitate the use of the marina.

“The gentlemen millionaires will come on their executive jets, get on their yachts and go all over the Caribbean,” Pastora said. “All kinds and sizes of yachts will come – and they will pay.”

Far more primitive vessels brought Spanish explorers, who discovered the San Juan River delta in 1539, and christened a settlement as San Juan del Norte in 1541. More than three centuries later, Great Britain laid claim to the region under the guise of protecting native Miskito Indians.

A Miskito king renamed the settlement Greytown in homage to the governor of Jamaica, a British subject, and the name lingers unofficially today.

What propelled the port into world headlines was the 1848 California Gold Rush. Would-be prospectors flocked from the U.S. East Coast to Central America in their quest to reach the California mines.

Shipping baron Cornelius Vanderbilt made three trips to San Juan to bring his Atlantic and Pacific Steamship Co., which already was operating to Panama. Vanderbilt’s Nicaragua route was cheaper and at least two days shorter than the journey through Panama, and throngs clambered aboard his vessels.