This is interesting.
Ed Leedskalnin was from Latvia, moved eventually to Homestead Florida, where he built a castle from coral limestone.
Of course, "how did he do that?" is always a good question. Ed would say "I understand the laws of weight and leverage and I know the secrets of the people who built the pyramids." Which of course also brings out the conspiracy theorists. But this guy gives a good explanation of how it worked. "Simple Engineering". Some serious metal working here if you want to reconstruct it for yourself.
tschus pyotr
-- pyotr filipivich. Discussing the decline in the US's tech edge, James Niccol once wrote "It used to be that the USA was pretty good at producing stuff teenaged boys could lose a finger or two playing with."