Gobeklitepe, a Neolithic archaeological site dating back to 9000 BC, is the oldest known human-made structure still standing ...

The circles follow a common design. All are made from limestone pillars shaped like giant spikes or capital T's. Bladelike, the pillars are easily five times as wide as they are deep. They stand ...

Over thousands of years, more calcium carbonate builds up making stalactites longer and longer and stalagmites taller and taller until they eventually meet, forming a limestone column or pillar.

VISITING six caves in a single day might sound daunting, but with the right preparation, you’ll encounter quartz crystal mounds, creatures adapted to life without light, 100,000-year-old pillars ...