Fancy! basically looks like a giant ship-in-a-bottle. It also has a giant sign at the top that says "Fancy!" on it. It is presumably on the opposite end of town from the Krusty Krab, seeing as Mr. Krabs mentions it being "someplace far away".
In "Krusty Love," Mr. Krabs and Mrs. Puff go on a date at the restaurant. When the bill comes, Mr. Krabs nearly has a heart attack and the restaurant was destroyed in an explosion when the hospital bill was added to the meal bill.
"Chocolate with Nuts"
In "Chocolate with Nuts," SpongeBob]], Patrick, Mary and her mother went to the restaurant and booked out the whole restaurant just to dine there. In that same episode, Squidward attempted to get in although he was not allowed to. SpongeBob has once rented the place using Tom's money and did so with Patrick.
"Le Big Switch"
In "Le Big Switch," SpongeBob also worked here in exchange, and brought Krabby Patties. It is revealed that the main chef of Fancy! is Mr. Le Schnook. SpongeBob had become the Exchange Chef of Fancy!. He brought Krabby Patties, but then brought back the popularity of the Krusty Krab, and Fancy! became bankrupt.