The immense wall of crumbling, whitewashed stone might have belonged to an abandoned castle. Turrets lined a roof that was no longer there and watchtowers poked the sky at each corner. This had been the province of horses, though, not kings, servicing a Portuguese cocoa plantation on the tiny island of Principe. All that remained inside the stone stables was rain forest overgrowth in shades of green and purple.

“This,” said my host, Claudio Torres, “is the place where you can finally confirm that nature wins.”

Looking at a map of the dual-island nation of Sao Tome and Principe, Africa’s second-smallest country — some 140 miles off the coast of Gabon, right on the equator — cannot prepare you for the otherworldly feeling you get when stepping off a plane there. Even before you land, it is difficult to imagine that those two dots of dense, tropical forest in the expanse of blue below are an entire nation.

Sao Tome, the larger of the two islands, has an international airport and a Portuguese-speaking population of 200,000. Roosters wander past pink and turquoise facades threaded with wild foliage in the capital city (also called Sao Tome). Drive 10 minutes and urbanity gives way to quiet fishing villages and banana groves.

It wasn’t until I got there that I realized I should have brought euros to either use or to convert to dobras — since, like many places in West and Central Africa, cash is king. Luckily, my lovely hotel, Omali Lodge, was one of the places that took credit cards. And when the banks opened after the weekend, I was able to exchange some British pounds.

Principe, an impossibly green island

My plan had been to stick to the main island, which is filled with enough lush rainforest, volcanic peaks and cocoa plantations to keep an intrepid tourist interested for days. But at the airport I met some workers for U.N.-Habitat, the United Nations agency in charge of improving human settlements, who had just returned from a project in Principe. One of the workers connected me with Torres, the ebullient Chilean running the project. Within a day, I was on a propeller plane to an impossibly green island with a population of around 8,000.

The only way to get to Principe is infrequent flights from Sao Tome, or a 24-hour boat ride that locals advised me not to take. But, oh, does that effort come with rewards. UNESCO designated the entire island a biosphere reserve, and at times it feels uninhabited. The largest gathering of people I saw was at the airport watching the spectacle of our plane touching down.

Tourists, too, are relatively rare, coming from mainly Europe or elsewhere in Africa to stay at isolated eco-resorts with access to some of the world’s most pristine beaches, like the hilltop Roca Belo Monte, Bom Bom, the island’s oldest resort; or the new five-star luxury tent complex Sundy Praia, with an infinity pool right on the ocean.

I had chosen the least resort-y option, Roca Sundy, both because its lack of beach access made it more affordable and because it’s the location of the U.N.-Habitat project. A hotel driver picked me up for a half-hour SUV ride on a red-dirt road, past bright, elevated homes and children running to school in cream-and-navy uniforms.

Some of those children live in a community on the Roca Sundy property, just opposite the hotel entrance. When I arrived, adults were cooking breadfruit in a wood-fired, outdoor kitchen. Young men passed a soccer ball back and forth. Many others were gathered at a bench under a large tree. “It’s called banco ma’ lingua,” said Torres, “which is where people go to gossip.”

I was learning many Portuguese words. A roca is a plantation. And senzalas, the small cluster of buildings where those cooks and athletes and gossipers live, were once slave quarters.

Slavery is inextricably linked to these islands. Portuguese colonialists began using Sao Tome and Principe as slave outposts in the 15th century, bringing forced labor from African countries like Angola and Guinea there to be sent to Brazil and the West. Many captives were kept on the islands to work the fertile volcanic soil, eventually leading Sao Tome and Principe to become the biggest cocoa producer in the world — with labor exploitation continuing long after the official abolition of slavery. Before the islands achieved independence in 1975, almost all of the land had been divided into rocas.

Roca Sundy, the hotel, just opened last year. It is a project of the South African tech entrepreneur (and second tourist in space) Mark Shuttleworth. Before his HBD (Here Be Dragons) venture capital firm swooped in, it was on the verge of being acquired by a palm oil company — a business that has led to the destruction of rainforests in Sao Tome. Principe’s citizens were so against the idea, said Torres, they went to their capital city to protest.

“Principe’s government has taken another path,” said Torres. “They want to preserve the island.”

Shuttleworth’s approach has to been to treat the hotel as a kind of living museum. He’s preserved the plantation house’s facade and its original grand wooden staircase and ornate ceilings. Outside, a plaque commemorates the spot where astronomer Arthur Eddington came during a solar eclipse in May 1919 and took photographs that were the first experimental test to prove Einstein’s theory of relativity.

I certainly felt conflicted staying in a former plantation house, not just as an American whose country is still reckoning with its own history of slavery, but also as a tourist who is constantly assessing the privilege of being able to travel to a place as beautiful as this. By supporting their economy and telling their stories, could I, in a very small way, help those who live here move forward?

When Principe’s economy collapsed after independence, its people adapted to living off the land — but that doesn’t mean they have adequate living conditions. Families of four are crammed into one-room senzalas. Most children have respiratory issues because the unelevated senzalas are filled with mold from Principe’s frequent rains. By request of the regional government, and with funding from HBD, U.N.-Habitat has proposed a voluntary resettlement project, with new, sustainable housing that has basic amenities. All but three of 136 households have signed on. In an effort to cater to individual needs and to give the town some character, each household has chosen its future dwelling from four designs.

As I wandered through the senzalas with Torres and Danilson Gomes, a young man from the community who serves as a liaison, we got a warm welcome. One woman in her 70s grabbed my hand and held it as we walked around. Others, who were introduced to me as community leaders, invited us into their homes. There is some concern that the resettlement is a way of clearing up the senzalas to accommodate expansion of the hotel. But Dani, our young guide, told me that he and his family are excited about the move. He will be leaving the island for the first time to attend a university in Portugal, but plans to come back, he said, “to help my country and help my people.”

Back to Sao Tome

I thought a lot about the spirit of community here on my last day back in Sao Tome. I had hired a local guide, Juliano Pina, to take me to the beaches and villages on the southern end of the island. On the way back, our SUV got hopelessly stuck in mud, three hours before my flight. A man named Ricardo who had been fishing nearby, came over and began gathering palm fronds and rocks to help with traction. More friends from his village joined in, as did another guide taking a tourist to the beach, until we had a team of nine or 10, many of them children, pushing with all their might. The car broke free. I handed out the last of my dobras, and made my flight with time to spare.

This, Juliano said, was the Sao Tome way: Leave no one behind. I like to think of it as a moment when nature could have won, but chose to give us a break.