The Magic Shop is a store that specializes on magic. It made its first appearance in the episode "F.U.N." in the episode "You Don't Know Sponge," Frank is seen working at the shop.
The exterior of the store has chains on it and on the top has the sign with a deck of cards.
The interior of the shop is revealed in the episode "You Don't Know Sponge." It basically has a bunch of magic items inside of the shop.