PUERTO PRINCESA — Rather than receiving the death penalty, some convicted murderers and rapists in the Philippines are instead sent to the so-called "prison without walls." At Asia's only such jail, 3,000 inmates live and work on 74,000 acres in one of the country's most beautiful regions.

Like many others, Carlo Mercedez works behind a computer in a simple office for eight hours a day — Monday to Friday. "Then I get weekends off to spend time with my family," he says.

But Mercedez isn't an ordinary citizen. He's one of the prisoners here at Iwahig Prison and Penal Farm, serving 30 years for rape. He begins his office day early, coming and going freely but expected to be present for multiple prisoner head counts during the day.

"At 6 in the morning we have head count, then we go back to prepare to go to the office at 8 a.m., he says. "We go home at noon to have lunch, then go back at the office at 1 p.m. At 4 p.m., there is another head counting. Then we can go home."

He has been at this unique prison for seven years. "I don't know when I will be released, but I already served my minimum sentence since 2011," he says.

Because of that, he is allowed to live in a halfway house with his wife and three young children, who attend school inside the open-air prison's facility.

Newer inmates serving time for murder, rape and dealing drugs are also free to work inside the prison grounds during the day, but they are kept locked up at night.

Penal Superintendent Richard Schwarzkopf Jr. is clearly proud of the fact that the facility is the only one of its kind in Asia. "We can talk about the uniqueness of Iwahig as a prison without bars maybe because of its vast location, natural environment and way of treating inmates," he says. "Some of our existing programs being undertaken can be adapted to other prison facilities."

On the vast grounds, there are all kinds of agricultural activities: rice farming, coconut plantations, chicken farming, a fish pond and vegetable farms. Based on their skills, inmates are given jobs ranging from farming to office work.

And the place has also become somewhat of a tourist attraction. Aldrin, who is serving 20 years for a crime he doesn't want to talk about, makes a living from selling handicrafts to tourists. "Those who want to see Iwahig Prison and Penal Farm and our historical buildings, please visit us," he says. "You can help us inmates by visiting this facility and buying souvenir items.”

Tourists visiting Iwahig — amy abanes via Instagram

Among his customers today is Jobert James from Manila. "When you hear the word "prison," normally you think of inmates being behind walls," James says. "So I thought Iwahig would be dangerous because inmates are outside. I was afraid that they might harm us because they're convicts. But my impression has changed. It's really safe here."

Making prisoners want to stay

During the Spanish colonial period, dissidents were exiled to this area, and it continued to be a penal colony under American rule. The prison is surrounded by thick mangrove forest, a mountain range and a highway, and these barriers are all that separate the prisoners from the outside world.

It's Xerxes Sebido's job as a prison guard to keep track of the inmates, but he says that four or five escape each year. "It's not easy to guard so many inmates, but the number of guards has been increased," Sebido says. "We have also implemented new security measures. And we are strengthening our rehabilitation and reformation programs. This helps the inmates to have a clear outlook on life and not think of escaping anymore."

Xerxes and the other guards also live on site, are given land here to build their houses so their families can live with them. "This is also one strategy of the Bureau of Corrections to keep the employees nearby when something happens like when a prisoner escapes."

Schwarzkopf says that, typically, those who escape are easily caught. He would prefer no one to escape, but instead of building walls, the strategy is to make prisoners want to stay.

"We have many reformation programs being implemented and enhanced such as the basic education and technical-vocational education for the inmates," he says.

Back at the office, inmate Carlo Mercedez is encoding a file on his computer. Though he feels lucky that he can still live with his family, he longs for life on the outside.

"It is not as happy as when you are a free man in society," he says.

Schwarzkopf says that only 10% of Iwahig's prisoners become repeat offenders after their release, a figure lower than the national average. The jail has also had no recent history of riots or mass breakouts.

Most other jails in the Philippines have brutal conditions, with inmates packed beyond capacity in dingy, airless cells and having to take turns sleeping.