Jane Jacobs wrote The Economy of Cities. Her thesis overturned the traditional theory that hunters settled down to be pastoralists who settled down to be farmers who formed the first cities. Jacobs theorized that successful hunters met at traditional campsites that became the first cities. Agriculture was a consequence of the cities. Where cities failed from war or other causes, the marginal peoples were cut loose from the missing center and became pastoralists chasing migratory herds.

Thus, successful hunters, enjoying the benefits of trade in their proto-urban campsites had plenty of time and ability to create those structures and others like them.

Also, note that 8000 years ago was 6000 BCE, a time when the Proto-Indo-European language was so successful that its speakers were ranging wide and diverging. These structures speak to that kind of intellectual ferment. And ferment it was, as beer and wine also date from that time.

Remember, it is in Kazakhstan, so even then, subject to government seizure.

A-very nice... How much?