But some of those who participated in those popular revolts feel the memorial doesn't honor the dead as much as it tries to paper over the continuing deep disputes over Egypt's future.
They say the military-backed interim government, which was brought to power after the July 3 coup that ousted Islamist President Mohammed Morsi is seeking to impose its control over what they see as an intrinsically anti-authoritarian space.
The inauguration comes a day before the anniversary of some of the fiercest confrontations between protesters and security forces on a street adjoining Tahrir Square, in which at least 45 people were killed by police in 2011. The day is expected to bring new rallies and, it is feared, new unrest, as it did last year, when clashes broke out.
Several hundred marched Monday evening in their own commemoration for the date, converging on a square a few blocks away from Tahrir where they set up a stage with a banner listing the names of those killed on Nov. 19, 2011 and 2012. They also sought to distance themselves from both the military and Morsi's Brotherhood.
"Down with traitors, whether military, old regime or Brotherhood," read a large poster they carried read, with pictures of some of those killed the past 2 ½ years, including some who died in the post-coup crackdown on the Brotherhood.
Activists were quick to point out the bitter irony of the government erecting a Tahrir memorial to the "martyrs," when there is no effort to prosecute police or military officials over their deaths and there is less official tolerance for protests. Soldiers routinely block the often-deserted square with armored personnel carriers and barbed wire on days authorities fear protests and clashes could reach the central Cairo plaza.
"No transitional justice starts by building a memorial in Tahrir," said political activist Rasha Azab, who took part in clashes in 2011 and 2012. "I have no doubt that this memorial will be destroyed soon. It doesn't represent anything."
Tahrir has been the symbolic heart of protest throughout more than 2 ½ years of Arab Spring revolt in the country. First, it was the main stage for the 18 days of protests that ousted autocrat Hosni Mubarak in February 2011. Then it was the scene of frequent protests by opponents of the military, which took over direct power after Mubarak's fall - repeatedly leading to deadly clashes with police and troops.
Finally, it was a main venue for protests against Morsi, the first post-Mubarak president, and his Muslim Brotherhood, culminating in marches by millions nationwide that prompted Morsi's ouster.
Since then, supporters of the military and the new interim government have effectively claimed control of the square.
The memorial construction is part of a government plan to show the country has regained stability. In Tahrir, municipal workers are laying new grass and flowers in the center of the roundabout.
Interim Prime Minister Hazem el-Beblawi inaugurated the memorial's base amid tight security, with all entrances to Tahrir sealed off by police. Authorities will hold a competition to design a statue to be placed on the pedestal, dedicated to the "martyrs of the two revolutions" - referring to the revolt against Mubarak and the wave of protests against Morsi.
"We are sending a message to the nation's innocent martyrs: Our people will never forget your sacrifices, you made your names immortal with letters of light, and you sacrificed your souls for the coming generations to live in dignity," el-Beblawi said during the ceremony, as a uniformed band played the national anthem and nationalist songs.
Since Mubarak's fall, successive leaders have sought to impose control on Tahrir through refurbishment and clean-up campaigns. Disputes previously erupted when workers tried to paint over revolutionary graffiti.
But this is the first move by authorities that ostensibly aims to honor the revolutionaries.
Watching workers lay stones at the memorial Saturday evening, Amr Suleiman, a bank worker, praised the government's efforts to claim the square from what he described as incessant dissent.
"This is perfect," Suleiman said. "It's better than the sit-ins and all the thugs, thieves and beggars who were hanging out here."
Mahmoud Osman, who came to the square with his wife and two children waving Egyptian flags, said he was happy the government finally is honoring those who died demanding change.
"This step should have come long ago," Osman said.
On Tuesday, multiple groups plan rallies to mark the second anniversary of the deadly clashes on Mohammed Mahmoud Street, which begins at Tahrir and leads to the Interior Ministry. The clashes began on Nov. 19, 2011 when police cracked down on protesters against the then-military rulers, and the violence went on for several days.
On last year's anniversary, three people were killed in clashes that broke out during protests against the police and Morsi.