Bohus explosion
1566 CE.
Shown on the map at 57.862°, 11.999°.
The Bohus Bang (Swedish: Bohusiska Smällen), as it is traditionally called in Swedish historiography, was a devastating explosion which occurred at Bohus Fortress in March 1566, during an assault by Swedish forces. The explosion was deliberately triggered by the fortress's Danish-Norwegian defenders in order to destroy the so-called 'Red Tower', which had been captured by the Swedes.
Text from the Wikipedia article Bohus Bang, licensed CC BY-SA 4.0.