In Cappadocia (central Turkey) there are millenia-old settlements carved out of volcanic tuff. You can hike down a valley and see structure after structure, not

In Cappadocia (central Turkey) there are millenia-old settlements carved out of volcanic tuff. You can hike down a valley and see structure after structure, not protected in any way, just out thre for anyone to climb into and explore. Churches, domestic dwelling, tombs... it was amazing. But the most common type of structure was a simple cave dug into the rock, with fifty to a hundred niches carved into the walls, and then the door was bricked uo with just three shoebox-sized openings left in them. We eventually found a guy there who represented himself as a guide, and he told us that these were pigeon coops, which the folks who inhabited these settlements used for their eggs. Which made no sense to me. Pigeon eggs are tiny. That's an awful lot of work for an egg the size of your thumb. But what makes perfect sense is to keep pigeons for their droppings. The place is practically desert. The soil is infertile. But with fertilizer... you could survive.