HistoryNeolithic (c. 9600–8200 BCE)Southeastern Turkey (Upper Mesopotamia)low confidence

The center points of three enclosures at Göbekli Tepe form a near-perfect triangle whose sides each measure approximately 63 feet.

Notes on verification

Confirmed by peer-reviewed study (Haklay & Gopher, Cambridge Archaeological Journal, 2020) and corroborated by multiple independent science journalism outlets reporting the same 19.25m/63ft equilateral triangle finding. [cascade flags: aggregator_dropped_primary_exists | tier=unverified indep_score=0.3 clusters=2 claim_tier=notable] [rescored 2026-09-15: curated origin-host map (PR #65); unclassified hosts no longer scored as aggregators]

Sources