This is a monument in the very heart of Nuremberg. Until a few weeks ago the little cobblestone hill underneath was inhabited by little kids crawling up and sliding down. Nowadays it's under siege by folks carrying Smartphones with battery packs. You're right, they play Pokemon Go. From this monument one can access several PokeStops and Arenas without moving.
I am very curious how long it takes for the kids to claim their hill back.
Maybe the re-conquering of the hill will be a Meta-Pokemon-Game: Kids try to catch human Pokemon players in a gamificated way.
As a last notice: The name of the monument is "Narrenschiff" (Ship of Fools). Nomen est omen?