With hundreds of things to see in Berlin, few tourists pay attention to what lies under their feet.
But once you know they exist, you begin to come across them with surprising frequency.
Two Stolpersteine outside of a building in Heidelberg, Germany for Max and Olga Mayer.
They both escaped Germany in 1939 via Switzerland and Spain to the USA and survived the Holocaust.
Demnig has now laid over 70,000 stones all over Europe and Russia.
Stolpersteine in Switzerland mostly remember people who were caught smuggling illegal written material at the German border.
They were caught by the Nazis after they had invaded France, and were deported toMauthausen-Gusen concentration camp.
About 7,000 Spanish people were held prisoner there, and were subjected to forced labor.
Such is the demand for these plaques that a request can takesix monthsto fulfill.
Despite its vast appeal, not everyone supports the drive.
In 2004, the Munich city council banned the installation of Stolpersteine.
Despite this there are about two dozen Stolpersteine in the city, but on private lands.
Michael Friedrichs-Friedlander, the craftsman who makes each Stolperstein, spoke in support of the project.
I cant think of a better form of remembrance,he says.
If you want to read the stone, you must bow before the victim.
The Stolpersteine blocks before they are installed.
Photo credit:PFriedmann/Flickr
Stolpersteine in Berlin.
Photo credit:Lorie Shaull/Flickr
Stolpersteine in Leipzig.
