Most People Have No Idea This Unique Tunnel In Hawaii Exists

Approximately 450 feet underground, below the streets of Oahu, sits a true feat of engineering: a massive, little-known tunnel, a rail car and subway named the Howling Owl and 20 massive fuel tanks the tunnel system was built to store. This is the Red Hill Underground Fuel Storage Facility, a top secret military facility built during the early 1940s for wartime use.

For a more comprehensive lesson about the tunnels history and construction, be sure to watch this video uploaded by the U.S. Fleet Forces Command in 2011, less than 20 years after the site was declassified.

Did you know about this impressive fuel storage facility hiding underneath the island? Learn about another little-known little know feat of engineering and wartime relic, the Waikiki Natatorium, here.