The tower was made from PVC pipes and fittings, copper plumbing bits and foam core.
This is one of the completed bunkers from the front, but you also get a good view of one of the large platforms. The bunkers stand one Necro level high, 3 inches, while the platform in the background is three levels, 9 inches.
This is the largest structure Nick has on his boards for right now. While there is one other tower built and a few others in mid-construction, this one is the current tallest and his favorite.
The lowest level of the tower with the copper conduits running from the ceiling into the main structure: