Could paranormal activity be explained by beings entering our world from other dimensions? According to some Ancient Astronaut theorists, entities that have been described as ghosts, angels, and extraterrestrials are actually visitors from unseen realms — and they are among us even now.

Throughout the ancient world, structures were built to mirror the constellations in the night sky–and, in most cases, this is only apparent when they are viewed from high above the Earth. Is it possible these structures were designed as messages for extraterrestrial visitors? Or were they puzzles left here on Earth for us to solve?