The top left photo was taken in Darmstadt, on the campus of the university. The sculpture is called “Bedrohter II” (the threatened II) by Waldemar Grzimek.
The top right lion is one of several in the palace garden of Schloss Schwetzingen, in southwest Germany.
The bottom left photo was taken in downtown Düsseldorf. The sculpture is called “Auseinandersetzung” (fray, dispute) and is by Karl-Henning Seemann, who has erected the same two figures in three more towns in Germany. Here is a photo of both figures – unfortunately it was raining which marred the photo (and it didn’t help that we were on our way back from sampling the local beer, either).
The last photo was taken in Berlin. The two figures depicted are Karl Marx (sitting) and Friedrich Engels; the artist is Ludwig Engelhardt.