Sixty years ago yesterday, on 30 October 1961, the Soviet Union detonated the most destructive bomb ever designed:
The bhangmeter results and other data suggested the bomb yielded around 58 Mt (243 PJ), which was the accepted yield in technical literature until 1991, when Soviet scientists revealed that their instruments indicated a yield of 50 Mt (209 PJ). As they had the instrumental data and access to the test site, their yield figure has been accepted as more accurate. In theory, the bomb would have had a yield in excess of 100 Mt (418 PJ) if it had included the uranium-238 fusion tamper which figured in the design but which was omitted in the test to reduce radioactive fallout. Because only one bomb was built to completion, that capability has never been demonstrated. The remaining bomb casings are located at the Russian Atomic Weapon Museum in Sarov and the Museum of Nuclear Weapons, All-Russian Scientific Research Institute Of Technical Physics, in Snezhinsk.
In the summer of 2020, Russia declassified a 40-minute documentary film about the explosion, which you can watch here:
It's fascinating, not only for its direct content, but also for the historical fun of trying to figure out which parts are total lies and which parts are merely whitewashing. (When they start talking about the lack of significant explosion effects on nearby settlements, that game gets more interesting.)