This may just be one of my favorite pictures ever. Looking back at the citadel through the craggy opening of the tunnel on the escarpment side. The sign to the left of the citadel's entrance looks as though it's suggesting all manner of "adult" pleasures inside, but in full that sign says, Children may enter ONLY under ADULT supervision. Many child-centric events take place at this museum, and the combination of delicately pointy junk sculptures, historic 19th century masonry and precipitous drops surely drive the kids' chaperones to distraction.