PRETORIA (AP).- Martha Mahlangu can't bear to visit the prison where her son, an anti-apartheid guerrilla, was hanged. But she says it's important that other South Africans see the gallows the government opened as a monument Thursday.

The new memorial recreates the place where political prisoners like Solomon Mahlangu climbed the stairs to face their executions, never struggling and sometimes even singing anti-apartheid songs.

Martha Mahlangu, an 87-year-old former maid, hopes visitors to the gallows will contemplate her son's sacrifice.

"Solomon only thought of freedom, to free the black man," she said in an interview in her Pretoria home. "He never thought of himself, only about seeing the black man free."

Her voice faltered when she tried speak about being invited to take part in a series of events this week at the gallows at Pretoria Central Prison. She sat on her porch in a neighborhood set aside for blacks under apartheid that today remains predominantly black and poor.

She said she was instead sending her eldest son and a nephew to Thursday's inauguration by President Jacob Zuma of the gallows and the death row block housing it as a national memorial and museum.

She also sent her son and nephew to a traditional ceremony Wednesday during which relatives of those hanged offered prayers and burned incense in remembrance.

Zuma toured the building Thursday morning at the start of the ceremony to open the site, accompanied by several Cabinet ministers and George Bizos, a prominent campaigner against the death penalty who was also former President Nelson Mandela's lawyer.

The anti-apartheid militants who were executed "were terrorists or trouble makers to the authorities then," Zuma said in a speech after his tour Thursday. "But to their people and families, they were freedom fighters who wanted to see a free, democratic and nonsexist South Africa."

Death row was in a low, brick building with imposing oak doors just outside the main block of Pretoria Central Prison. The gallows were abandoned after the death penalty was abolished in 1995.

On Thursday, a sign on a freshly painted wall along a hallway leading to the gallows told visitors some 3,500 South Africans were hanged over the last century. "Of these," it said, "130 were patriots whose only crime was fighting oppression."

Not all those hanged were executed in Pretoria, but many of the most prominent were.

South Africa's highest court ruled in 1995 that the death penalty was a cruel, inhuman and degrading violation of the country's post-apartheid constitution. Executions had been on hold since 1989, as a debate raged that touched on the executions of anti-apartheid militants and on whether there could be a fair or just way of deciding who would be hanged.

Solomon Mahlangu was among the class of 1976, young South Africans radicalized by a student uprising in Soweto that year that was met by a brutal police crackdown. He was 20 when he left South Africa to train in Mozambique and Angola with Umkhonto we Sizwe, or "Spear of the Nation," the armed wing of the African National Congress, which celebrates its 50th anniversary Friday.

One of Solomon Mahlangu's trio got away. Another, the only one accused of firing a gun, was so badly beaten in custody he was judged unfit to stand trial. Prosecutors did not dispute that Solomon Mahlangu never fired a gun, but he was convicted of sharing his comrade's deadly purpose.

He was hanged on April 6, 1979. The next day, his mother was brought to Pretoria Central and shown her son's plain wooden coffin. She remembers thinking it looked very small.

The gallows was destroyed in a smelter after the death penalty was abolished. Visitors to the site will see a replica: Seven nooses dangling from iron loops over a trap door.

A prison employee who said he had been a death row guard helped ensure the new museum's details are correct, down to the thickness of the ropes. He refused to give his name, saying he feared reprisals from South Africans who might consider him a murderer. But he said he was just doing a job.

David Kutumela, a 56-year-old anti-apartheid activist who like Solomon Mahlangu began his fight after the 1976 uprisings, helped campaign to create the gallows memorial. He and other activists visited the gallows often as it was transformed into a museum.

"Walking up those 52 steps, we all think, 'It might have been us instead of Solomon,'" he said.

Kutumela said the museum is for South Africans as young as or younger than he and Solomon Mahlangu were when they became militants. He said he worries today's children "don't even understand how this freedom came about."

In another sign of how far South Africa has come, the top spokeswoman for the prison department is an ANC veteran who trained as a teenager in the same Angolan camp where Solomon Mahlangu became a guerrilla.

Sibongile Promise Khumalo has a hug for everyone she meets, including the white guards at Pretoria Central who once escorted ANC fighters to their deaths.

Khumalo said she embraced the museum project, speaking with the families of those hanged instead of delegating the emotional job.

"I cried with those people," Khumalo said. "We were reopening wounds for them."

She said the goal was to offer closure to the families, and to society a chance to confront the wounds of the past and then move on.

"I know South Africans are forgiving," she said. "We need to help each other carry out this journey of remembrance."

Copyright 2011 The Associated Press.