TOP 15 LARGEST UNDERGROUND Structures

From colossal underground cities to scientific test sites and nuclear facilities, there are many secret places that can be found deep underground. In today’s video we will count down the top 15 largest underground structures in the world. #Structures #Structure #top15 Several segments are licensed under creative commons For more video information, please visit our website. The Top Fives show brings you informational and entertaining top five videos! Join us and subscribe for more. Follow Josh on Instagram! Founder and producer of the Top Fives show. Stay up to date with the channel and everything YouTube and business related! Follow us on Facebook! Contact us via the email form here: Note: The videos featured on the Top Fives channel are for educational and info