There are details of the story of the "Watchers," a group of angels who descended to Earth, took human wives, and produced giant offspring called "Nephilim", who became destructive and ultimately led to the corruption of humanity, eventually causing the Great Flood: This chapter is considered a key part of the narrative regarding the fallen angels and their consequences. 

Key points from Enoch Chapter 7

The Watchers' transgression: 

The angels, led by Semjaza, chose human wives and began to teach them forbidden knowledge, including sorcery, astrology, and the art of weaponry. 

https://youtu.be/-x8DmeUSjVU

The birth of giants: 

The children born from these unions were enormous giants, describing as being three thousand ells tall.

My thoughts: Now I can believe in angels but giants? Now that definitely makes this sound more like fantasy then a historical account. 

https://youtu.be/z8Zfc-jfPCc

The Earth's complaint: 

The Earth itself is described as accusing the lawless giants of their destructive behavior.