Why do travelers, presumably out for a good time, head to former island prisons like San Francisco’s Alcatraz, South Africa’s Robben Island or – my personal favorite – Costa Rica’s Isla San Lucas? Is it to contemplate the way societies mete out reward and punishment? To wonder how we'd hold up if we ended up in such a place? To scan the perimeter and plot our escape?

For me it's also – perhaps perversely – about standing in a rundown cell and imagining it as a kind of bare-bones writing retreat. In some prisons there’s a bed, a table and a toilet. Add pen and paper and you’re set. Being literally locked into a room of your own would provide a powerful incentive to finally finish that novel. You’d write your way out, creating worlds on the page to escape the box they’d stuck you in.

It was a man who did just that who drew me to San Lucas. Before I ever set foot on the island I knew the story of prisoner 1713, aka José León Sánchez, inmate at San Lucas for nineteen years. Talk about an enforced retreat. León Sánchez entered prison barely literate but emerged a published author, printing his first works in prison on a press he made following instructions in Popular Mechanics. He wrote more than two dozen books, but his most famous is based on his time on the island: La Isla de los Hombres Solos (The Island of the Lonely Men).

He writes of inmates laboring in the tropical sun, breaking rocks and harvesting salt from the sea, dragging their leg irons. “I felt with my own flesh,” León Sánchez writes, “the fire of steel, the long months of the dungeon, my hands chained with irons, the contempt for my condition as a human being. In the penitentiary I found out that a man can descend until he turns into a dog, or less than a dog.”

But León Sánchez also rhapsodizes about the island’s beauty, all the more affecting when contrasted with the horror of the prison. “There isn’t anything prettier in San Lucas than these summer months,” he writes. “Trees germinate and blossom ... the foam on the sea laughs and each wave rears boisterously in the wind ... yellow butterflies appear by the thousands.”

From 1893 to 1989 the island was so synonymous with cruelty and isolation that there are no towns named San Lucas in all of Costa Rica. But recently the island became a wildlife refuge and historical monument.

When I was there, my friend and I and two park officials were the only souls on the island. The only living souls, that is. The place was rife with ghosts. They were in the bat-infested prison church, the old dining hall invaded by strangler fig trees, and most of all in the dank and dilapidated cells. You can feel the weight of the former inmates' waiting, their caniando – doing time. These spaces wouldn’t invite lingering except for the messages left on the walls. But unlike León Sánchez, many of the inmates were illiterate, communicating not in words but in pictures.

Soccer players make goals, knives drip blood and a jaguar stalks toward a cell's one tiny window. Crosses abound, as do sad-faced Jesuses and beatific Virgins, one with her robe flaring like a river delta. Most of all, though, there are women in various states of undress. Near the shadowy back of one cell, a larger-than-life woman totters on high heels, her rust-colored bikini purportedly drawn in blood.

There wouldn’t have been much privacy to enjoy the racy pictures. These rectangular cellblocks, hardly bigger than my studio apartment in San Francisco, have low ceilings, few windows for fresh air, and each held 60 to 80 men. This is not the room of one’s own that writers dream of.

Out in the prison courtyard you could feel the ocean breeze and hear the waves lapping against a nearby beach. What a relief it must have been for inmates to come out here, even for a few moments.

And what a relief to leave the prison behind and head down an overgrown path to where palm and mango trees arch over clean sand, with sweeping views across the water. León Sánchez wrote of an inmate swimming out into the bay, maybe from this very beach, with a dead pelican strapped to his head for camouflage. The warden, cruel to human beings but a lover of birds, had forbidden anyone from harming pelicans. But he could apparently tell a dead one from a live one, and shot this one out of the water.

Our escape from Isla San Lucas is significantly less dramatic.  But I come away from the island with even more respect for León Sánchez, who with the help of pen and paper escaped his identity as prisoner 1713, transporting himself and his readers into other worlds. Ironically, his best-known work brings people to the island he most wanted to escape—an island that also haunts me, years later, so much so that I write myself and my reader back onto its cruel and beautiful shores.