Most of the world's great megaliths have never been dated directly

1. 35 of 40 famous megaliths are dated only by association. Only one — Nan Madol — has a direct date on its building stones; three have no date at all. The ages of the Great Sphinx, Carnac, Sacsayhuamán, Tiwanaku and others rest on material found near them, on texts, or on style. Pre-registered as H7; confirmed after an independent review. The ten monuments where a first direct date would matter most →
2. The Great Sphinx enclosure has never been dated directly. No chlorine-36, U-series or carbonate dating of its walls has been published. A paired chlorine-36 comparison against Khafre-era quarry faces could test whether the enclosure is older than the conventional date — or confirm it. The Sphinx weathering case →
3. Monte Verde, the textbook vindication, was reopened in 2026. A Science paper argues for a mid-Holocene age. The challenger's own radiocarbon dates match the older age, and the key occupation layer was destroyed decades ago — so settling it now depends on archived material. Monte Verde →
4. Real anomalies are usually partly right. Of ten celebrated vindications, only three held cleanly; five were partly right and two are still open. All seven refuted cases stayed refuted. Observation O1 →
5. "It can't be that old" objections fail more often. 25% of objections that proved wrong argued from the accepted model, vs 8% of those that held — the predicted direction, but weak so far (p = 0.18). Hypothesis H4 →
6. The first data scans. Dismissed old radiocarbon dates in a 173,946-date global database do not line up by region (a null). A second scan for dates older than each region's accepted first arrival flagged ten unfamiliar early-Americas sites. Discovery track →

These are leads, not discoveries. Each rests on published sources checked by a separate skeptic agent, and each names the test that would settle it — to be run by credentialed specialists with permits.

Update 2026-09-23. Correction to point 4: we had counted later refinements (dates tightened, interpretations adjusted) as partial failures. Rating each anomaly's core claim instead, 7 of the 10 celebrated vindications hold and 3 remain contested; Gunung Padang is now 'unsupported' (paper retracted, claim not disproven) rather than 'refuted'. Thanks to the outside reader who pointed this out.