Burger King has a restaurant inside Madrid Atocha, but its pretty hidden away. You’ll find it right at the end of the embarcadero area of the station. This area is the one with the tropical gardens so it’s not that difficult to find.

Embarcadero. Burger King as on the right hand side.

Embarcadero. Burger King as on the right hand side.

With your back to the station platforms, Burger King as at the extreme right-hand side area of the embarcadero.