Ancient Aliens — Episode 4: Extraterrestrial Engineering

You are watching the episode Extraterrestrial Engineering Host Giorgio Tsoukalos probes the series archives to explore remarkable ancient structures that defy conventional explanation. From the precisely cut stone blocks at Puma Punku, to the gigantic temples of Malta, and the megalithic city of Nan Madol, could these mysterious sites contain evidence of extraterrestrial contact in the distant past?