Location : a neglected army site in the midst of the fields; an abandonned subterranean water reservoir that used to provide water for the fire brigade.
The space is in complete darkness, the picture below was taken with a flash, only then was it visible of how the room looked like.
In the partitions between the concrete beams are frames. The frames will light up one after the other following the movement of persons jumping into a void.
Almost impossible to capture with my type of camera the pictures are of poor quality, but I was quite impressed with the feeling of this dark space (the pictures show more details of the building than actually visible in reality).