Events that happened, that we have records of, and that nobody has fully explained — Dyatlov Pass, the Mary Celeste, Tunguska, the Taos Hum, the Hessdalen lights.
On the night of February 1, 1959, nine Soviet hikers led by Igor Dyatlov cut their tent open from the inside and fled into a -25°C blizzard on the eastern slope of Kholat Syakhl in the northern Urals. All nine died. Bodies were recovered over four months. Two had skull fractures; one had crushing chest injuries; clothing on three carried traces of radioactivity. The case stayed officially unsolved for sixty years.
On the morning of June 30, 1908, an explosion equivalent to roughly 10–15 megatons of TNT flattened approximately 2,150 km² of Siberian taiga near the Stony Tunguska River. No crater was found. The first scientific expedition reached the site nineteen years later. The leading explanation today — a stony asteroid airburst at ~5–10 km altitude — fits most of the physical evidence, though competing hypotheses about composition (cometary, stony, carbonaceous) are still debated.