Mayan
From Memory Alpha, the free Star Trek reference
The Mayan Human civilization existed in the southern regions of North America and northern Central America from the 1st millennium BC through the 9th century.
Kukulkan, a benevolent alien being, periodically visited ancient Earth cilvilizations and influenced their architecture and agricultural development, and was worshipped as a god. Kulkulkan visited the Mayans in the 6th century, and influenced the Egyptian and Aztec cultures as well. Kulkulkan was discovered by the crew of the USS Enterprise in 2270. (TAS: "How Sharper Than a Serpent's Tooth")
