Between the abandoned hut and the Peräkorpi it lies.
At its apex Valyria was the greatest city in the known world, the center of civilization. Valyrian steel was invented in Valyria and was used to make weapons and various other items of unparalleled quality. Being spell-forged steel, it is the spells and magic that make the steel special.
Tyrion: How many centuries before we learn how to build cities like this again? For thousands of years the Valyrians were the best in the world at almost everything and then...
Ser Jorah: And then they weren't.