This is a diner and pizza parlor that was open in the 1970s. This is where a time-travelling Timmy Turner made his father eat fatty foods to make him a lose as part of a greater scheme to prevent his father from winning a trophy.
The building is a small square shaped structure with a glass panel window in front, large lettering that reads "Pizza" on the front, as well as a sign reading "John's" and "Ice Cream". Inside there are tables and booth seats.
In the episode, "Father Time!", after Timmy accidentally melted his dad's trophy with Heat Vision, and ignoring Wanda's suggestion to apologize, he instead follows Cosmo's advice and travelled back in time to stop his dad from winning the trophy in the first place. He made his dad eat un-nutritious meals at this fast food chain, made him walk with hollow blocks tied along his food, and told him scary stories which made his dad lose the race. As a "reward" from coming in last, he was sent to Lil' Tyrant Dictator School. After seeing the dystopian future that he created where his dad was alone, never married Mrs. Turner, and was the dictator of the world, Timmy again went back to correct the damage he caused to the timeline, returning it to normal before going back to his own time to apologize to his dad for melting the latter's trophy.