Here's a look at homeless-constructed caves found along Tuloumne River

People live in houses like this all over the world, some are simply spectacular! There are underground places in Turkey that have many levels, and the people even could keep animals and food storage in them. These probably are not too safe only because of the water, and flooding or drowning, but they are amazing. Housing is going to look like it always has before the 'modern' times because the system does not work for many.