The Pennsylvania Department of Environmental Protection says it has learned where the lead in Blue Hole Creek is coming from.

At the bottom of a 500-foot deep cave lies a stunning discovery - a deep blue hole hidden from the world above. In this video ...

Nestled along Route 66 in Santa Rosa, New Mexico, the Blue Hole is a captivating artesian spring renowned for its ...

The Dragon Hole is about 990 feet deep, surpassing the third-deepest blue hole, Dean’s Blue Hole, by over 300 feet. The Taam Ja’ Blue Hole is more than twice as deep as Dean’s Blue Hole.

Geologists working in Yellowstone National Park discovered a new pool of strange light blue water this spring. Using ...

“Blue holes” are underwater sinkholes that open below the seabed. The hole, dubbed “Green Banana,” opens up at 155 feet below sea level. The bottom of the hole is at a depth of about 425 feet.

It's a limestone cave, to be exact. The Great Blue Hole contains stalactites and stalagmites below the surface, some 40 feet in length. And as with any good cave, more mysteries lie within.