Contemporary architecture's approach to space is fairly linear: enveloping a specified volume within some form of material construct. But if we take a look at humanity's first intentional dwellings, it becomes clear that they were much less premeditated.
Rather than manmade areas to be furnished with pride, our earliest homes were naturally occurring cave lairs that offered hunter-gatherers temporary protection from the elements and potential predators. It wasn't until the appearance of agriculture that our ancestors took permanent, built residences. To this day, troglodytism — or cave living — continues to be connected to ideas of societal disassociation and a hermetic desire to exist outside of orthodox architectural norms. And yet, from Northern China to Western France and Central Turkey, hundreds of millions of people still choose to spend their lives at least partially underground.