In the depths of the San Lázaro rock-shelter in Segovia, Central Spain, archaeologists from the Complutense University of ...

Inks Bridge, the river has carved gigantic stepping stones from pink granite and considerately surrounded them with deposits of gravel and water-buffed rocks that include not only gobs of granite ...

and a dozen smooth river rocks balanced in a neat line on the ridge of a chunk of gray granite, like petrified travelers in an airport security line. This idyllic little ripple in space-time was ...