Crystal Cave is over a million years old and stretches about three miles, he says. Only a small fraction of caves in the ...

Experts believe the modified stalagmites are evidence of a planned occupation of the caves by ancient societies.

From lively cafés and hilltop castles to scenic cobblestone streets, Slovenia’s capital city, Ljubljana, has plenty to ...

Tulelake, CaliforniaFormed by half a million years of volcanic activity, Lava Beds National Monument contains the highest ...