It is a big place which stores many aquariums. On the front of the place, there are pictures of fish being captured and text saying "Many Colors" in yellow text, as well as "Low Low Prices" in purple and green text.
Role in episode
While SpongeBob is traveling across the surface world with many other fish, Pearl Slabs picks the fish tank they're in and puts it inside the aquarium. The fish are able to escape, however due to Patrick's strength. Since Patrick fell in love with a fish in the aquarium, they end up rescuing many fish from the Land Aquarium.