Dubuffet finished this in 1988 and called it an anti-monument: 78 feet of his Hourloupe pattern — a jigsaw of white, black, red and blue — rising out of a park on the Île Saint-Germain, visible across the lawn like something that landed there. The part people miss is that it is hollow. A spiral staircase runs up the inside to a small observation platform, open only sometimes, which is very much the joke Dubuffet was making about monuments.