Found the following pictures of megaliths on one of the Russian sites. There are no names for locations, have to do more searching. Commentator's theory is that these stones were somehow heated to the temperature above 1000C, something that made them flexible to the point where they could be cut or fitted into. But wouldn't specific resonance frequency be able produce a similar effect? With heat or some other effect of making the stones more "flexible"? Changing their physical or chemical properties?
_http://www.webpark.ru/comment/67810
_http://www.webpark.ru/comment/67810