There are three great unsolved natural mysteries in the history of mankind.
1. The Mythical Massacre of Mohenjo Daro in India more than 3000 years ago.
2. The bizarre explosion which occurred at 9 a.m. on May 30, 1626 A.D. (the sixth day of May, the sixth year of Tianqi in the Ming Dynasty), the day after the Dragon Boat Festival, in an area near the gunpowder magazine of the Wanggong factory in the southwest corner of Beijing.
3. The major explosion which occured in the Evenk Autonomous Okrug in Siberian Russia at 7:17 a.m. (UTC 0:17 a.m.) on June 30, 1908.
(TL: https://www.sciencedaily.com/terms/tunguska_event.htm)
Yes, when Sindalor looked towards the northwest of the Greater Khingan Range, the first place Sheyan thought of was the site of the Tunguska explosion, one of the three great natural mysteries!
