About 250 m2 of basalt wall. Climbing to a maximum height of 5 meters. Top tropics possible via iron railing. Of the 3 classic locations, the boulders here are on average the most difficult. Since 1985 the "Think Pink Boulder Bolwerk" of Amsterdam!
A climbing competition was held here in 1989, and around that time 78 routes were marked and rated for difficulty. The paint of most of the routes has become unreadable, and the area has since been extensively rebuilt.