As far as 90 feet underground and 100 feet thick, miles of coal seams are continually burning in the U.S. and elsewhere, releasing toxic fumes that funnel up to the surface
Secret tunnels at Shepherd's Bush Underground station in London
The fires below - High Country News
London Under: The Secret History Beneath the Streets by Peter Ackroyd
Deep Underground Military Bases - Secret Military Bases
The Longest Minute
Hidden Deep Guide for Beginners, Tips and Tricks
Explore Network to Freedom Listings - Underground Railroad (U.S. National Park Service)
By 10, I knew all about the impact of a nuclear blast': growing up in the shadow of the bomb, Nuclear weapons
31 Years Ago: Rage Against the Machine Release Their First Album
Coal-seam fire - Wikipedia
Photos: Wildfires Rage Across Greece - The Atlantic
Through Time Into Healing: Discovering the Power of Regression Therapy to Erase Trauma and Transform Mind, Body and Relationships: Weiss, Brian L.: 9780671867867: : Books
Life after Deepwater Horizon: the hidden toll of surviving disaster on an oil rig, Deepwater Horizon oil spill