In attempting to build card structures that (somewhat) resemble real buildings, I have started by doing the exercises found in the only book on the topic. I will create my own structures later (put your requests in early), but for now it is important to learn the basics.
The easiest shape to create when card stacking is a pyramid-like structure, and with the proper icing on the cake you get the idea that this could be the pyramid in tikal.
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[video]
Other variant is possible also
Another variant on the Mayan Pyramid? I am sure there is, and I would love to see your ideas. Do you stack (if so, do you have pictures/video)?