1) In Norse mythology, Ragnarok is a cataclysmic event that signifies the end of the world. It involves a series of apocalyptic battles and natural disasters, leading to the destruction of the gods and the world as it is known. From the ashes, a new world and a new generation of gods emerge.

2) The Mariana Trench in the western Pacific Ocean is the deepest part of the world's oceans, reaching a depth of approximately 36,070 feet (10,994 meters).

3) The Berlin Conference in 1884-1885 divided Africa among European powers and set the stage for the colonization of the continent.

4) The world's first insurance policy was issued in 1347 in Genoa, Italy. It insured against the risk of maritime trade.