I’ll give you one guess to figure out what this is. Without a caption is just looks like a big hunk of cement in a side yard that I’d want to have removed as soon as I moved in. However, if you guessed that it was a BBQ pit, you win the prize — the prize being bragging rights that you guessed right. 
We like to BBQ here in Georgia, but I can’t say I’ve seen a pit quite like that one. My first thought would be to sit not put my steak on it!