What looked like an ordinary underground pipe turned out to be an entrance into a massive river cave. Inside, explorers found ...

Tanzania is home to some of the most breathtaking waterfalls, which are a must-visit for all nature lovers. These hidden gems ...

A self-confessed ‘eccentric’ has spent 30 years hand-digging an other-worldly labyrinth of underground caves 20ft below the ...

Hidden in eastern Nevada’s rugged landscape, Cave Lake State Park remains one of the Silver State’s best-kept secrets – a dazzling blue oasis that somehow escapes the attention it so richly deserves.

Launch your boat into the Ohio River or explore a 55-foot cave with fascinating pirate history in this state park in southeastern Illinois.

That’s the sensation waiting for you at Black Chasm Cavern in Volcano, California – a subterranean marvel that transforms an ordinary day trip into an expedition worthy of National Geographic. Tucked ...