Check out these mind blowing megalithic stone structures. See more in this Ancient Aliens compilation. Watch all new episodes Fridays 9/8c; Stream Next Day, and stay up to date on all of your favorite shows on The HISTORY Channel website at #HISTORY #AncientAliens Find out more about the show and watch full episodes on our site: Ancient Aliens is now a podcast! From the age of the dinosaurs to ancient Egypt, to continued mass sightings in the US, each episode gives historic depth to the questions, speculations, provocative controversies, first-hand accounts and grounded theories surrounding this age-old debate. Available wherever you get your podcasts: "Ancient Aliens" explores the controversial theory that extraterrestrials have visited Earth for millions of years. Don't miss a video! Subscribe NOW: @HISTORY?sub_confirmation=1 ABOUT THE HISTORY CHANNEL: The HISTORY® Channel, a division of A+E Global Media, is the premier destination for historical storytelling. From best-in-class documentary events, to a signature slate of industry leading nonfiction series and premium fact-based scripted programming, The HISTORY® Channel serves as the most trustworthy source of informational entertainment in media. FOLLOW HISTORY CHANNEL: Watch Full Episodes: Sign Up For History Emails: Browse Topical Videos: Facebook: Instagram: TikTok: @history X: YouTube: @HISTORY Copyright Notice: This video and my YouTube channel contain dialog, music, and images that are property of The HISTORY® Channel. You are authorized to share the video link and channel, and embed this video in your website or others as long as a link back to our YouTube Channel is provided. © 2025 The HISTORY® Channel How Were These Mysterious Structures Built?! | Ancient Aliens | History @HISTORY/