I still love that the basilica cathedral was designed upside down.

Stone only works under compression. If any area ends up under tension, it will just fall apart. String only works under tension, if it is under compression, it crumples. Critically, if you invert the model, the forces invert. The basilica was designed as a string model upside down. This made mismatched forces obvious, and is easy to correct.

Historical designers had a lot of tricks, that we have mostly forgotten, to make things work.