These two murals are some of the best known large-scale works here in Berlin. They were painted by street artist Blu in 2007-08 in reaction to changes to the working-class neighborhood, Kreuzberg. The mural on the right also celebrates the reunification of East and West Berlin, if you look closely, you'll see that one of the figure's fingers make the sign E and the other a W.
Sadly, the walls were painted over in December 2014 at the request of the artist in protest of the further gentrification of the neighborhood. These buildings were sold to developers and are slated to be torn down to make room for luxury apartments. You can read more about the development plans here and you'll find more murals at Monday Mural.