The buildings are more than symbols, we have no clue how they were built, just theories, but remember there were no power tools before 1895. There were no cranes. Those massive Roman columns, were carved in perfect symmetry by hand tools?

The beings who built the cathedrals had methods and technologies of amazing power that we know virtually nothing about. They are artifacts of something that is now, presumably, gone.

The temple _is_ God's physical dwelling place