Bulb roof

An eye-catcher of the square is the canopy, which consists of a "bulb roof". The 24-meter high roof is supported by seven pillars. The roof contains 49 transparent air cushions in which air is continuously blown in by air compressors to maintain a slight overpressure. They have a diameter of about seven meters and are made of ETFE foil, which means they should be self-cleaning. The air cushions weigh little, but the total roof nevertheless weighs around 500,000 kg.

Due to its characteristic shape, the roof has already been given many nicknames. Some nicknames are the "Hardebollendak" (Hard bulb roof)(a reference to the Hardebollenstraat in the center, the former window prostitution street) and the "Koffiebekerhouder" (coffee cup holder). The AD held a poll from 13 to 14 February which should be the name of the roof. The winner in this poll was the name Honingraat (honeycomb).