This week on Ancient Aliens: Declassified, the show looks at whether ancient builders got some help from aliens when constructing some of the complex buildings that we still puzzle over today.
The planet is littered with the remain of huge and complex structures that were built by long-gone civilisations using relatively primitive technology. Archeologists have puzzled over just how some of these huge buildings were created, with countless documentaries on the likes of how the Great Pyramid in Giza was made.
There have been various theories about moving blocks on barges or using greased wooden poles and some have gone as far as recreating the methods.
However, some ancient astronaut theorists are wonder if they were directly helped or perhaps instructed by aliens with advanced technology and knowledge of engineering. They point to the similarity in design of many megalithic and even later structures in completely different parts of Earth. Pointing out that it fairly clear that many of these civilisations were not in contact with each other, yet seemed to have produced similar buildings.
Ancient Aliens: Declassified airs on Fridays at 8:00 PM on History Channel.