They were at the Bosnian site, and I've heard they have done so at other places, but that's kind of what I meant by hiding stuff. Depending upon who does it we don't always hear the results.
The guy that built the coral castle in Florida and died without telling anyone how he did it always fascinated me. He moved all those blocks by himself with no modern machinery. He claimed he was using forgotten ancient techniques.
Some little kids said they saw him doing it and he had two ice cream cones.
Some are speculating that might be stone shaped ice cream cone like implements that have been found at many archaeological sites and are usually dismissed as art.
A speculation I recently heard involved using intense sound beyond the human hearing range to move them. I have difficulty grasping how that'd work with two stone ice cream cone shaped objects....
Just sharing what little of the mystery I know.
how mysterious..