I don’t know what they are called: basement storefronts? Half storefronts? Lower storefronts? In Bulgarian they are known as “klek shops,” since “klek” means “to squat.”
But whatever they are called, I was quite surprised to find a number of these in Sofia, Bulgaria:
The shopkeeper is located in a basement, and he / she sells things through the basement window.
I was quite surprised to find a real life example of this, since until now the only places I’ve seen pictures of these are very old photographs of London.