It's a big day in Berlin, where the city's memorial for gay Holocaust victims officially opened. The structure, set up near a larger Holocaust memorial, includes a video loop showing two men kissing and this message, "A simple kiss could land you in trouble."

Here's some more on the logistics:

The stone is 4 metres tall. The monument to the persecuted homosexuals is devoid of ornamentation, partly to deter vandalism and partly as a reference to the hundreds of plain, tomb-style stones making up the sprawling nearby Holocaust memorial.

The separate monument for homosexuals was ordered in 2003 by Germany's Bundestag parliament after lengthy debate over whether to commemorate all victims of the Nazis with one monument or separately.

Current research suggests 54,000 men and women were convicted of homosexual acts and about 7,000 killed in the camps. The dictatorship attempted to wipe out all dissent and any behaviour which did not serve the Nazi ideology.

The new monument, designed by Danish-Norwegian artists Michael Elmgreen and Ingar Dragset, contains a window that invites the visitor to look inside and see a film of a homosexual couple kissing.

The image is to be changed between two men and two women every two years. A text on the monument describes the Nazi persecution. The project cost 600,000 euros (935,000 dollars).

Sadly, no survivors made the event. The last known, out gay survivor of the Holocaust, Pierre Seel, died in 2005.