The Questiomark Tower is, as the name would suggest, shaped like a questionmark. Now, if you think about this, you'll realise it's pretty much technically impossible to build a tower like this, what with the gap between the point and the rest of the questionmark. Still, despite it bing technically impossible, the Tower has been built and added to the base by MrEdwardNigma. The fact that no foundations or support beams were used and that most of the tower just sort of hovers above the rest of the base only adds to the awe it inspires.
From the outside, the tower is huge and golden, and consist of two basics parts: a huge golden orb attached to the base, and everything else, hovering above it.
Little is known about the inside of Questionmark Tower, as the only AMENite to enter it so far is MrEdwardNigma himself. What is know though is that there's a flight of stairs running up to the upper part of the tower from the orb, even though those two parts aren't actually connected. Furthermore, the tower can be hermetically sealed and it is rumored to contain an "impossibility matrix", a machine generating impossibilities.
