Secrets of Lost Empires is a two part television series produced by PBS Nova, Boston (WGBH). Both series explore experimentally how ancient civilizations achieved notable constructions without modern machinery and construction methods. Each episode has guest experts who are challenged to develop and implement methods that may have been used. The original series was produced with the BBC and fully compiled in 1997 (although some episodes had been produced much earlier) and the second series was produced with Channel Four of the UK and fully compiled in 2000.