Buenos Aires, Argentina (CNN) -- Despite what has traditionally been regarded as a macho culture, Argentina has been viewed in recent years as a leader on gay rights issues in Latin America.
In 2002, Buenos Aires was the first Latin American city to grant civil unions to gay couples, and the capital is consistently ranked as one of the world's most gay-friendly tourist destinations.
During the last six months, five gay couples have been married in Argentina, which is a predominately Catholic country.
The upper house of Congress is set to begin debating Tuesday the legalization of same-sex marriage in the entire country. The initiative passed the lower house May 6.
During the past year Argentina has also taken steps to assist an often overlooked sector of the world's gay population: senior citizens.
Situated behind the tall, wooden doors of a century-old building in Buenos Aires, the Puerta Abierta ("Open Door") center is Latin America's first community center for gay senior citizens.
Since opening its doors in September 2009, some 120 gay seniors have participated in the center's activities, from movie outings and beach trips to therapy sessions.
On a recent Monday afternoon, 64-year-old political consultant Mercedes Sanchez was there to attend a group counseling session.
Sanchez says she had two serious relationships with men before acknowledging her true sexual identity. She has been living her life openly as a lesbian for more than three decades, but admits she never told her parents before they died.
"Back in that era, Argentine society was much different," Sanchez says. "My parents thought differently. It was hard for me to admit that I was different. But coming here and being with other people like me has helped me tremendously."
Despite the support that the center offers them, Argentina's gay retirees still say they face many obstacles and experience discrimination. Some of the Open Door center members say they lived much of their lives in conventional, heterosexual marriages, and only came out of the closest later in life. Many have struggled during the transition period.
"What we hear most from gay seniors is how they feel lonely and isolated," says Alejandro Viedma, a psychologist who counsels Open Door's members. "For young gay people, there are lots of possibilities for meeting people, like bars, saunas and cafés. But for older people, it is really more difficult."
Norma Castillo,68, and her longtime partner, Ramona Arevalo, 68, became Argentina's first legally-married lesbian couple on April 9. However, a week after the wedding, a judge annulled their marriage. Now the courts need to decide if their union is legally binding. Castillo is convinced it is.
"We didn't fight for this in vain," Castillo says. "This was like a calling. Since we started, we've always had the rights of gay senior citizens in mind.
Aside from Castillo's and Arevalo's marriage, judges have allowed four other same-sex marriages since December, although at least two of them also face legal challenges and are tied up in the courts.
Regardless, gay activists are optimistic that momentum will continue in their favor. They are lobbying lawmakers to pass the historic gay marriage legislation, and also plan to fight for additional rights, like adoption.
"We are slowly achieving change here, and this is inevitable, because the world is changing," says Open Door co-founder Graciela Balestra.
"Fortunately, we get to be the protagonists in these historic changes."