http://www.bbc.com/future/story/20190611-how-to-build-something-that-lasts-10000-years

Life in many medieval towns revolved around constructing a cathedral, a massive undertaking that took generations of work by everyone from artists and architects to prisoners of war. - https://www.nationalgeographic.com/history/history-magazine/article/gothic-cathedrals-architecture-medieval-europe