That is correct, but the subterranean dodecahedron itself is merely the portal that the interdimensional lizard beings use to move between our world and the 4-dimensional hyperdodecahedron.

Your comment made me check if it actually was possible, and what the platonic solids in higher dimensions were.

http://math.ucr.edu/home/baez/platonic.html

https://en.wikipedia.org/wiki/120-cell

There's also this fantastic Numberphile: "Perfect Shapes in Higher Dimensions"

https://www.youtube.com/watch?v=2s4TqVAbfz4

At last, I've found the end of the internet!