When it comes to looking back in history, I've found this to be one of the more interesting topics, all over the world there is evidence of Nuclear/Atomic Warfare in Pre-History yet, it seems to be ignored on a mainstream level for the most part. When the first atomic bomb exploded in New Mexico, the desert sand turned to fused green glass. This fact has given certain archaeologists a turn. They have been digging in the ancient Euphrates Valley and have uncovered a layer of agrarian culture 8,000 years old, and a layer of herdsman culture much older, and a still older caveman culture. Recently, they reached another layer of fused green glass.
Here's an article by Brad Steiger, Author of many books including "Worlds Before Our Own." this one focuses on the evidence that supports the use of Nuclear/Atomic Warfare in Pre-History. And helps to possibly explain the Vitrification of Stone Sites in UK. Etc.
Numerous evidence of Pre-Historic Nuclear War exists: Columns of Smoke Rose as if from a Mighty Furnace