A few years ago I read that the streets of New York were created using Dutch stones, which can still be seen in Soho & Tribeca. The article also said theses stone where never removed from Manhattan, but paved over. I didn't think there was much validity to this claim. Think about it from a structural perspective. To build lasting streets with a solid foundation the stone, if the actually existed everywhere would be removed. Well, as of last week, the street I live on is being re-paved. Mind you I live nowhere close to downtown. Low and behold the cobbles do exist.