[Centurion2000]

The missing sun temples! (Where are they?)

Well if I had to just guess I'd say they were under some sand somewhere in Egypt.

[Young Werther]

There was a shuttle mission that used an earth penetrating radar to scan the globe. I remember radar pictures of Egypt which disclosed geological features which were hidden by the sand. The change in the course of the Nile, eons ago, was readily visible. Might a search of these images be fruitful?

[Little Bill]

The Question is not the where but the why.

[raygun]

I opt for the hidden in plain site theory.