Patomskiy Crater

A limestone egg the size of a stadium, pushed up from below in the Siberian forest. Locals call it the Fire Eagle Nest and don't go.

The Patomskiy crater (Irkutsk region, documented since Kolpakov's 1949 geological report): a 40-meter limestone cone with a central mound, tree-ring evidence of a growth anomaly dated near 1841-42, and expedition findings (2005-10 — the 2005 expedition leader died en route, feeding the lore) supporting either cryovolcanism/gas breakthrough or a deep-seated fluid event; no meteoritic material found. It remains genuinely unresolved in the Russian geological literature. The node is the hidden-earth file's live anomaly: a real formation, real expeditions, no accepted mechanism.