BERLIN - Germany unveiled a memorial Tuesday to the Nazis' long-ignored gay victims, a monument that also aims to address ongoing discrimination by confronting visitors with a video image of a same-sex couple kissing.

The memorial -- a sloping gray concrete slab on the edge of Berlin's Tiergarten park -- echoes the vast field of smaller slabs that make up Germany's memorial to the Jewish victims of the Holocaust that opened three years ago just across the road.

Work will begin nearby this year on a third memorial to honor the hundreds of thousands of Roma and Sinti -- Gypsy -- victims of the Nazis.

Berlin's openly gay mayor, Klaus Wowereit, said the new monument was a reminder of the struggles that still confront gays.

"This memorial is important from two points of view -- to commemorate the victims, but also to make clear that even today, after we have achieved so much in terms of equal treatment, discrimination still exists daily," Wowereit said as he inaugurated the memorial alongside Culture Minister Bernd Neumann.

Nazi Germany declared homosexuality a threat to the German race and convicted about 50,000 homosexual men as criminals. An estimated 10,000 to 15,000 of them were deported to concentration camps, where few survived.

Michael Elmgreen, co-designer of the memorial, said the video of the kiss was important to the project. "You can get acceptance on an abstract level, but they don't want to look at us," he said.