The town of San Juan was built — alas, alas — on a floodplain that is routinely submerged under several feet of water. An elevated concrete sidewalk leads through the back half of town, connecting stilted homes perched malarialy close to stagnant, dirty water. Unsurprisingly, the town is lush and humid. Residents readily admit their waterlogged town is not prepared for the type of tourism that comes on airplanes.

In some ways, there are still more attractions to be found among the ruins of Old Greytown, the colonial ghost town whose only residents have been occupying graves for more than a century. A rusty iron fence divides four ancient cemeteries — “British,” “Catholic,” “Masonic,” and “Sabine,” for the nine Americans who died on the USS Sabine, a warship commissioned in 1858.

Visitors poking about the graveyards may get some giggles from English translations, such as how poor Captain Charles Smith “died to stop breathing.”

Silliness aside, the gravestones of Old Greytown — which have endured while the creeping jungle consumed everything else — are intriguing and haunting. The cemeteries are next to the new airport, offering a strange visual dichotomy of old and new. Still, it’s hard to imagine this area was once a hub for international trade and commerce.

Today, most tourism here is based at Río Indio Lodge, which is the easiest trailhead for the surrounding wilds. The lodge was built on a strip of elevated riverbank halfway between the ruins of Old Greytown and swampy San Juan del Norte, avoiding the drainage problems of both.

Rio Indio Lodge, which already has a jump on the tourism market, is expanding in anticipation that the new airport will bring more business. The lodge is working with the Smithsonian and George Mason University to develop a $300,000 animal refuge with elevated catwalks leading to tree-top viewing platforms, where guests will be able to watch jaguars feeding in the wild.

For the time being, the lodge’s 250-acre private jungle reserve provides the best access to Nicaragua’s massive and fabulous Indio Maíz Biological Reserve, a 4,500 square-kilometer virgin rainforest that is Central America’s answer to the Amazon. From here, you are just a paw’s reach away from animals that can bite or poison you. It’s an experience that’s as authentic and edgy as Nicaragua itself.

Just don’t fall asleep with banana breath.