I wouldn't want to sit by that "fire pit" if the wind is blowing wrong. Being that close to the house and a corner.... i can only imagine. Speaking of imagining.... i can't imagine building something semi permanent, like that stone, around a throw away kiddy pool. That's just me.
Pepsi introduced the first 2 liter plastic bottle in 1970 or so. Pretty sure the bottles the kid in the red shirt is touching are plastic 2 liter bottles. They needed those black plastic bottoms glued on to stand up straight.