When I was in Chengdu I visited Jinsha, which has lots of evidence of postholes: https://en.wikipedia.org/wiki/Jinsha_(archaeological_site) http://www.kaogu.cn/en/Chinese%20Archaeology/3/Discovery%20a... Granted, that's only 3000 years old.
A better example (which I just learned about-- I'm literally trying to google for the oldest post holes found :) ) is Monte Verde: https://en.wikipedia.org/wiki/Monte_Verde
> Radiocarbon dating of bones and charcoal in 1982 gave the site an average age of 14,800 years ago (calibrated), more than 1000 years earlier than the oldest-known site of human habitation in the Americas at that time.[2][8][9]
> In the initial excavation, two large hearths were found and many small ones as well. The remains of local animals were found, in addition to wooden posts from approximately twelve huts.
Archaeologists were able to use this technique at pompei, to learn exactly how vines & vineyard fenceposts were placed in ancient vineyards.