So I'm about a third of the way through Fire & Blood after four days of listening.
Perhaps the most interesting bit so far was the story of Arya Targaryen. She stole away on Balerion the Black Dread and disappeared for something like a year. No one knows for sure where she went, but the dragon returned her to King's Landing on the verge of death, being cooked alive from the inside with something writhing within her.
The septon who tended to her speculated that the dragon took her to Valyria. When they put her in an ice bath, he wrote that the things inside of her emerged, serpents with faces, serpents with hands, a slithering mass of them. The creatures died when exposed to the freezing water.
They also noted that Balerion was clearly wounded in several spots, including a nine foot long gash on his side that was still dripping with his steaming blood.
Makes you wonder just what the fuck is in Valyria. Really hope one of the remaining books takes us there, provided Martin ever actually writes them.