Secret Escape Tunnel from Grow Op Covert Escape Tunnel Cover Disguised as Stone A clandestine grow operation was built in an elaborate underground bunker in Tennessee a few years back. The escape tunnel entrance was concealed under a false ...

MonoVault Underground Gun Storage These MonoVault gun tubes from StoreGuns.com seal tight to preserve your gun in shipping or storage, even buried underground!

Secret Trap Door in Floor Leads to Underground Priest Hole These removable floorboards in Harvington Hall reveal a ladder down to an underground priest hole.

Secret Trap Door Leads to Underground Priest Hole This secret trap door leads to an underground priest hole for concealing traveling priests during the reign of Queen Elizabeth I.

Old Bank Vault Door This bank vault door is located in the basement of an apartment building in Memphis, TN.

Trap Door to Secret Room in Synagogue The Touro Synagogue in Rhode Island houses this trap door to a secret room below the floor. Traditional stories say Spanish and Portuguese Jews kept such secret rooms in their synagogues to hide ...

EHow has a simple tutorial on how to build a concrete underground storm shelter like this one shown.

Reliable Storm Shelters provides these solid steel constructed shelters intended to be used underground. They can be set into landscaping in a variety of ways to still allow easy access.

This secret bookcase door, posted by a member of Reddit, opens into a mile long tunnel leading to a nearby church.

This secret trap door is located in the floor of the Padmanabhapuram Palace in India.