Really ancient, not like the Johnny-come-latelies of classical Greece:
Neo-lithic proto-urbanism, apparently a widespread pattern of large megasites shortly after agriculture, then abandoned, for reasons unknown.
http://io9.com/how-farming-almost-destroyed-human-civilization-1659734601 Indus Valley Civilization, painting a less egalitarian picture than I'm familiar with, but still high in standardization, low in warfare, and with lots of plumbing. Possibly matrilocal marriage.
http://io9.com/a-civilization-without-war-1595540812 I note both articles are written by the same author, who Has A Book, so possible bias.
See the
DW comments at
http://mindstalk.dreamwidth.org/410691.html#comments