Apenkooien/The Floor is Lava
Apenkooien is a kind of tag (tikkertje) usually played in Dutch school gyms. Players are not allowed to touch the floor, they can only move about via mats, vaulting horses, bars, ropes, etc. Anyone touches the floor has to leave the field of play, kind of like the floor is lava.
Come join this event if you like sportive activities! Or if you like going for a beer after. Which will most likely happen.
