Why does Cappadocia have stone towers and caves?

Cappadocia has stone towers because ancient volcanoes left thick ash that became tuff, a rock that erosion can shape into tall pillars. It has caves because people learned the same rock was firm enough to stand, yet soft enough to dig into for homes, churches, storage, and shelter.

Some pillars wear harder stones on top, because that tougher layer shields the tender rock below while weather eats the sides away. Families and monks made rooms inside cliffs, and whole underground towns included air shafts, wells, animal spaces, kitchens, and painted chapels.