Interesting. I didn't know they were building things that far back. "Hidden in plain sight” is how archeologists described a recently revealed, 3,000- year-old Maya structure at the Aguada Fénix Mayan ruin in Mexico’s Tabasco State." Aerial LiDAR Uncovers Oldest Maya Site Yet
How did certain Native Americans groups like the Mayans become as developed as they were? They had a writing system and were very good with architecture and mathematics. What was different about their environment?
Cairn of Barnenez is 7000 years old "In a first phase, a slightly trapezoidal mound of 32 m by 9 to 13 m was erected. It contained 5 chambers and was surrounded by a double kerb. The first phase favoured the use of dolerite." Barnenez - Wikipedia
So many things about the Mayans seem similar to the Egyptians. Similar architecture,hieroglyphic writing,elaborate artistic depictions,astronomy,mathematics etc.
not quite that similar. the pyramid shape is the simplist way to make something tall from loose components that won't fall over. 3,ooo yeas is not that old, when human remains, dating more then 13,ooo years old have been found and verified in the western hemisphere. many cultures have built and then abondond high density living conditions, when population levels exceeded the capacity of their infrastructure technologies, or environmental conditions changed, sometimes as a result of their doing so. something our own world embrasing development is in high risk of facing in less then a hundred years, possible sooner.
and of course there are some even a good bit older then that. a place that translates as potbellied hill for example.