BASSEM MROUE, ZEINA KARAM, Associated Press

BEIRUT (AP) — For decades, the mere mention of Tadmur Prison was enough to send chills down a Syrian’s spine.

The notorious facility in the desert of central Syria was where thousands of dissidents were reported to have been beaten, humiliated and systematically tortured for opposing the Assad family’s rule.

This weekend, it was demolished by the Islamic State group, which took over the site near the ancient town of Palmyra last month, bringing mixed emotions from many Syrians who wanted it to remain standing so future generations would know its horrors.

"They destroyed our memories, our catastrophe and the walls that we leaned on and told our stories to," said Ali Aboudehn, a Lebanese who spent four harrowing years in Tadmur. "They destroyed the land that absorbed our blood because of torture."

The sprawling prison — once one of Syria’s darkest secrets — is located a few miles east of Palmyra, a desert oasis famous for its Roman-era colonnades, temples and artifacts. There were fears that the Islamic State militants might destroy the 2,000-year-old heritage site.

Instead, over the weekend, they focused their destructive efforts on Tadmur Prison.

The extremists released photos that showed men carrying plastic containers apparently filled with explosives. A video showed parts of the prison in rubble.

Osama al-Khatib, a Syrian opposition activist who fled Palmyra for Turkey three weeks ago, said the militants destroyed only the part of the prison that held members of the military, including army defectors. He said the facility where political prisoners were held is still intact. His report could not be independently verified.

Located about 250 kilometers northeast of Damascus, Tadmur Prison is part of a walled-off military complex that includes military and civilian units as well as an air base. Former prisoners say it could hold up to 7,000 inmates, although the number fell in recent years. By the time IS swept into Palmyra last month, the inmates had been moved elsewhere and the prison was empty.

Hassan HassanInside Tadmur Prison.

Under President Bashar Assad’s father and predecessor, Hafez Assad, the prison held mostly members of the outlawed Muslim Brotherhood, pro-Saddam Hussein Baathists and loyalists of the late Palestinian leader Yasser Arafat.

The bloodiest incident in Tadmur’s history came in June 1980, a day after members of the Muslim Brotherhood staged a failed assassination attempt against Hafez Assad. In retaliation, troops belonging to Assad’s brother Rifaat reportedly entered the prison and shot up to 1,000 prisoners who belonged to the Brotherhood.

Al-Khatib, who was not born at the time, said his parents told him about the incident, recalling that they heard shooting for much of that night. Afterward, the government took bulldozers from Palmyra to dig mass graves in the nearby Oweimer Mountain just north of the town, he said.

Hassan HassanTadmur Prison

"People would pass by the prison, but no one dared look inside," al-Khatib said.

Aboudehn recalls the first day he entered Tadmur in 1988, nearly a year after he was detained in Damascus for allegedly having contacts with Israel, Syria’s archenemy.

He had to walk blindfolded and handcuffed between two rows of men who kicked, pushed and beat him with clubs and metal rods. His nose was broken and he bled profusely.

Aboudehn showed the torture marks on both his legs, as well as his permanently dislocated right arm.

He recalls the warden telling a gathering of detainees shortly after they arrived: "You have come to your end, there is no mercy here. God is prohibited from entering the jail. We are God. We decide if you live or die."

Aboudehn said he was regularly beaten and humiliated during the four years and eight months he spent there. The jailers never referred to him with his real name, calling him "No. 13" instead.

Hassan HassanISIS members preparing to blow up Tadmur Prison.

He was held in a cell with about 150 inmates who all shared one bathroom. For food, each prisoner received three loaves of Arabic bread, an olive and a teaspoon of marmalade a day, as well as one egg that was shared among five inmates.

Prisoners were completely cut off from the outside world, Aboudehn said, recalling that the first time he knew the Berlin Wall fell and the Soviet Union collapsed was in 1993, well after those events happened.

Aboudehn broke down when he recalled looking through a keyhole and seeing a soldier urinating in the food that he and those in his cell were about to eat. He refused to eat but didn’t have the courage to tell the others what he had seen for fear of being killed by his jailers. Instead, he told his fellow inmates that he wasn’t feeling well.

"I decided I will not say anything then, but one day I will go out and tell what the regime used to do with us," said Aboudehn, bursting into tears. "May God curse this regime and those people who despised humanity!"

When he was moved to Sadnaya Prison, a facility near Damascus where dissidents also were known to have suffered mistreatment, he said it was like "a five-star hotel" in comparison.

Aboudehn, who heads the Committee of Lebanese in Syrian Prisons, regretted the destruction of Tadmur by the Islamic State militants.

Militant website via AP, FileThis photo released on Saturday, May 30, 2015 by a militant website, which has been verified and is consistent with other AP reporting, shows Tadmur prison, blown up and destroyed by the Islamic State group in Palmyra (Tadmur in Arabic).

"They demolished a historic symbol that should have stayed, because in every room there were people who were killed," he said.

A 2001 report by Amnesty International titled "Syria: Torture, Despair and Dehumanization in Tadmur Military Prison" catalogued routine abuses against prisoners, including the use of iron bars, whips and cables.

"Tadmur Prison appears to have been designed to inflict the maximum suffering, humiliation and fear on prisoners and to keep them under the strictest control by breaking their spirit," it said.

Blowing up the facility may have been part of attempts by the extremists to gain popularity among those who suffered at the hands of the Syrian government. But residents and former prisoners called it a huge mistake.

Yassin Al Haj Saleh, who spent 16 years in Syrian prisons and wrote a book about his experiences, said he was saddened by the news, "as if they have destroyed my home."

Militant website via AP, FileThis photo released on Saturday May 30, 2015 by a militant website, which has been verified and is consistent with other AP reporting, shows Tadmur prison, blown up and destroyed by the Islamic State group in Palmyra.

"I dreamt that I would visit it someday. … I had imagined that visiting the prisons where I spent time would serve as closure," he wrote on his Facebook page.

"The destruction of a prison that was the symbol of our slavery is the destruction of our freedom as well. Of course, it’s a huge service to the Assad regime of slavery," he added.

Al-Khatib said he and his friends used to dream of entering the prison one day and documenting what happened inside.

"Now that Daesh destroyed the crime scene, it is more difficult to know what happened," he said, using an Arabic acronym for the Islamic State. "I am totally against destroying it, although it represents a dark page of Palmyra and Syria’s history. It should have stayed as a witness to this dark period."

Syrian opposition figure Radwan Ziadeh wrote on his Facebook page that Tadmur Prison "should have been kept as a museum for future generations as evidence of degradation of human beings during the Assad rule."

"Daesh turned it into rubble today."