Three months ago, Rep. Robert Kastenmeier (D-Wis.) went to Georgia to inspect one of America's genuine hellholes, the Atlanta federal penitentiary. Opened in 1901 during the McKinley administration, it now has some 2,100 prisoners packed into cell blocks that are 45 percent overcrowded.

The usual history of litigation is here: confinement suits against prison administrators, consent orders to rectify sordid conditions and dollar figures -- $65 million in this instance -- on the cost of renovations.

Kastenmeier, who is chairman of the House subcommittee on courts, civil liberties and the administration of justice, could have visited other prisons to find those conditions. He found that Atlanta is unique for different reasons: it cages 1,857 Cuban prisoners who are not serving time for crimes and have almost no legal rights and few hopes of ever being released.

"The current living situation for the Cuban inmates," Kastenmeier recently reported, "is intolerable considering even the most minimal correctional standards. These detainees . . . are worse off than virtually all other federally sentenced inmates."

Part of the brutality includes the physical violence. Since 1981, the Atlanta prison has had nine homicides, seven suicides, 158 suicide attempts and 2,000 cases of self-mutilation. Most inmates are confined in "lock-down" status, meaning they are locked into their cells for 23 hours a day.

In two of the five cell blocks holding Cubans, eight prisoners are crammed into one cell for an average space of 7 by 4 feet per inmate. The psychological violence, as dehumanizing as the physical, is in knowing that they are, in Kastenmeier's words, "stateless persons."

When the Cubans arrived in the land of the free, stripping their freedom was the first welcome. Fifteen months later -- a year-plus of tasting U.S. justice -- about 123,000 of the Cubans had been released from jail, with most of the rest being herded into Atlanta's cells. Lawsuits filed on behalf of the imprisoned won the release of a few, but fair hearings and equitable protections were ignored for the majority. No procedures have been established to show that individual prisoners, if released, would be public threats.

Recently, allies of the Cuban prisoners -- including the American Civil Liberties Union and the National Council of Churches -- called on the United Nations to investigate. The indefinite and arbitrary detention of the Atlanta inmates, said the ACLU, violates the 1948 Declaration of Human Rights and customary international law. Some 300 of the Atlanta prisoners have been held continuously since 1980, with the rest having been released but later recaptured for alleged revocation of their parole.

How fair have the rejailings been? "The guidelines now used for making parole revocations," the ACLU wrote to the U.N., "are vague, lacking in any specific criteria, and provide for no prior notice, hearing, interview or even for input of any kind from the parolee himself before the parole may be revoked."

The Justice Department sees it differently. Those who are back in prison, an official says, "are people who have been convicted of serious crimes. They cannot be safely released to society and are being held against the time they can be returned to Cuba. We had one agreement to return them , which Cuba broke off, and we're waiting for a renewal."

That brings the issue back to Kastenmeier's finding: the prisoners "are being held because their continued presence in the community and in the country has been deemed unacceptable to the government. In spite of numerous legal challenges, these detainees remain virtually without legal rights."

Earlier efforts to provide relief for the prisoners have been futile, even on the personal level. A Catholic priest, Joseph Fahy, who has a doctorate in theology from Harvard, began volunteering in the prison in October 1983. He celebrated mass, held Bible classes and let the men know that he cared for them and took their side.

In September 1985, the priest was told by prison officials to stay away. He wasn't a model volunteer. Fahy, it seems, had had several letters to the editor printed in the Atlanta Constitution, all of them reporting on what he had seen and learned while ministering to the Cubans. A prison official explained that Fahy's public disagreement with "government policies" toward the inmates made him unfit to work within the system.

The gag order -- look but don't tell -- is in keeping with the other degradations suffered by the Cubans. Fahy says that he found "no incompatibility between my service as a priest and exercising my duties as a citizen to describe what I found in prison."

The priest was as deluded as the Cubans: he thought it was a free country.