In ep. 2 of Hardcore History's Blueprint for Armageddon, Dan Carlin says "...Germanic barbarians in formerly Roman territory looking up at crumbling aqueducts and wondering what sorts of giants once roamed the Earth that could build stuff like that". Well, who did they think built them?

by YUnoZOOM

Additionally what did other Europeans think about the various Roman ruins around Europe, until their true origins became known? Was there criticism or pushback against claims that they were Roman-built?

oakcan

Not to discourage other answers, here is /u/BRIStoneman and /u/itsallfolklore take on the question of giants building Roman buildings in the context of England.

IlluminatiRex

What is the context of this quotation? Isn't Blueprint for Armageddon about WWI?