For millions of years, the land we now call the United States has been home to towering prehistoric beasts, strange sea creatures, and lush ancient forests that no longer exist. Evidence of this ...

Mammoth Cave, the world's longest known cave system, stretches 426 miles under Kentucky. The cave's limestone began forming 330 million years ago when the region was submerged under an ocean. Visitors ...

Excavated from a hayfield near Warrensburg, Fossil Pond and its limestone evoke an age 300 million years ago when a vast sea covered much of the Midwest, including Kansas City. Gary Rhoades From a ...

The Fossil Forest in Dorset is a stretch of southern English coastline peppered with living mounds of limestone that hide the remains of cypress trees from the late Jurassic period. When you purchase ...

The black "marble" tombstone is made of limestone that likely came from Belgium. International Journal of Historical Archaeology A mysterious black tombstone that marked the final resting place of a ...