RIYADH, Saudi Arabia — Nobody was home at the dusty brown campus of the reintegration center for recovering Islamic extremists. The swimming pool was still. The lights were on at the gallery of art therapy works, but there were no visitors. Not a slip of paper was out of place at the psychological and social services unit.

The beneficiaries of the Saudi government program, which helps prisoners re-enter society, were on furlough for family visits for Eid al-Adha, the season of the Feast of the Sacrifice, leaving the place eerily empty, like a U.S. college campus on Christmas break.

Only a painting in the gallery offered a glimpse of the religious tolerance that is a hallmark of the program: It was of a woman smelling a flower, her hair uncovered and flowing, against the night sky.

The program, with its campus in Riyadh, and another in Jeddah, grew from a counterterrorism campaign that began in 2004 to re-educate citizens who had made their way home from jihadist training camps in Afghanistan and others influenced by them.

About 6,000 men have gone through some form of the program, among them 137 former detainees of the U.S. military prison at Guantánamo Bay, none of whom were convicted of war crimes.

The last Guantánamo detainee was sent to the program in 2017, just before President Donald J. Trump dismantled the office that negotiated transfers.

Now the question is whether and how the center fits into President Biden’s efforts to close the prison at Guantánamo, which opened more than 20 years ago to hold terrorism suspects seized around the globe in the aftermath of the Sept. 11 attacks.

Over the years, the United States has held about 780 men and boys at Guantánamo Bay, with about 660 there at its peak in 2003. Saudi citizens were of particular interest because 15 of the 19 hijackers in the Sept. 11 attacks were Saudis.

The Trump administration released just one prisoner from Guantánamo, a confessed Qaeda operative who is currently serving a prison sentence in Riyadh under an Obama-era plea agreement. The Biden administration repatriated another Saudi citizen in May, but under an agreement to send him for psychiatric treatment for schizophrenia, not jihadi rehabilitation.

More than half of the detainees currently at Guantánamo have been cleared for release but must wait for the Biden administration to find a country willing to take them in with security arrangements. Most are from Yemen, one of several countries Congress considers too unstable to receive men from Guantánamo.

Other detainees are in plea negotiations with discussions about whether convicts could serve their sentences in foreign custody.

The Obama administration had tried to shut down the prison, and Saudi Arabia was one of the countries that figured prominently in the resettlement plans. Another was Oman, which received 28 Yemeni men in a highly secretive project that found them wives and homes and jobs, so long as they did not tell their neighbors that they had done time at Guantánamo, according to former detainees.

None of those men who were resettled were ever tried for war crimes.

The Obama administration sent 20 prisoners to the United Arab Emirates, mostly Yemenis but also several Afghans and a man from Russia. But the country essentially jailed them and then abruptly repatriated all but the Russian, drawing human rights protests that the returnees risked persecution.

With that program deemed a failure, the Biden administration has been looking for other options for cleared captives, chief among them the Yemenis.

A recent visit to the dusty brown campus in the outskirts of Riyadh highlighted one possibility.

The program was founded by and named for Prince Mohammed bin Nayef, a former interior minister who had close ties to U.S. intelligence agencies. When he was forced out by the kingdom’s de facto ruler, Crown Prince Mohammed bin Salman, the program was renamed the Center for Counseling and Care.

As described by managers, the program blends classes on nonviolent interpretations of Shariah law with physical fitness, recreation and counseling aimed at returning those who graduate to their families.

Or, as one staff member called it, undoing “the brainwash that happens” when a young man is drawn to religious extremism.

A library features recommended reading about successful Saudis, “the right people, in order to avoid the wrong role models, not the way that turns you into darkness or death,” Wnyan Obied Alsubaiee, the program’s director, who holds the rank of a major general, said through an interpreter.

One book recounts the story of a Saudi man who studied in New York in the 1970s and rose to prominence in civic life back in his homeland, including a role in a Saudi-American dialogue after the attacks of Sept. 11. Another is a biography of a former government minister, “Building the Petrochemical Industry in Saudi Arabia.”

General Alsubaiee said two former prisoners of Guantánamo in the Saudi prison system would be accepted into the program once they completed their sentences. One is Ahmed Muhammed Haza al-Darbi, the confessed Qaeda terrorist released by the Trump administration. The identity of the other is not known.

The director bristled at portrayals of the program as a five-star hotel for extremists.

“This is not a prize,” he said. “They are not prisoners anymore. They have to go back to society. We want them to feel accepted, and that this is another chance.”

Of the 137 men sent to Saudi Arabia from Guantánamo, some by way of Saudi prison, 116 rejoined society and have stayed out of trouble, 12 were recaptured, eight were killed and one is “wanted,” according to a program fact sheet.

None of the men were identified by the Saudi government during the visit. But some of the dead are known, notably those who were sent during the George W. Bush administration and then fled to Yemen, where they joined Al Qaeda in the Arabian Peninsula.

In Riyadh, the program’s participants live in pods, individual bedrooms arranged around a courtyard with a mosque, kitchen and small open air stove for making tea on cool desert nights.

As described by program administrators, the Saudi participants’ first visits home are short but evolve into long-term stays with family — for example, the two-week holiday furlough that virtually emptied the center in July.

The nation’s security apparatus is unseen but present. The director is a military official and security employees and care providers dress identically in the classic white robe and red checked head covering favored by government workers and businessmen. In the gym, a guide gestured to a camera in a corner of the weight lifting area and explained that facial expressions there were under surveillance.

But on this visit, Saudi transparency only went so far. Nobody would say how many of the program’s 200 slots were occupied, or when the most recent person or longest resident arrived.

At the gallery, an art therapist, Awad Alyami, described his program as an opportunity for the men to express their feelings and for program sponsors to evaluate them.

One painting was an expressionist take of the crowds circling the Kaaba in Mecca, Islam’s holiest site, but clockwise rather than the ritualistic counterclockwise. Program staff members were concerned about the depiction of the holy site, and had the artist meet with a cleric.

One section of the gallery showcases the work of former Guantánamo prisoners.

“A lot of weird stuff here,” Dr. Alyami said.

The section has no sign but stands out for its image of a guard tower, razor wire and men in orange uniforms. Other program participants’ art tended toward desert scenes and other Saudi themes.