There's a massive steel maze in Belgium that looks pretty cool. The creators are Pieterjan Gijs and Arnout van Vaerenbergh, who also built the steel church in Haspengouw that changes structure depending on the viewer's perspective.
The labyrinth, which is located at the C-mine arts center in Genk, uses 186 tons of five-millimeter-thick steel plates and consists of a kilometer maze of corridors with walls as high as 5 meters. The installation looks quite complicated. But, it is nothing compared to the giant corn mazes in the U.S.
[h/t: La boite verte]