Detective Comics#223(1955)

A man decides to start a phony Batman museum in Gotham City in order to amuse some people and earn some money. He invests a great amount on money creating the place, full of props and designed to look like the Batcave. The operation is successful and even Bruce Wayne and Dick Grayson enjoy the place. However, Commissioner Gordon disapproves of the whole concept and demands the place to be closed. Bruce decides to talk to Gordon as Batman, but he is soon distracted by a man who is an agent for a potential buyer of Wayne Manor. He offers twice the mansion's value before being shooed away. Bruce is suspicious of such sudden offering and he follows the buyer's agent as Batman. He learns that the buyer is a criminal who wants access to the caves underneath Wayne Manor for a hideout and to find some loot another criminal told him about while he was locked up. Since Bruce won't sell the house, the crook decides to dig his way into the cave. Batman and Robin decide to move everything from the Batcave to the Batman Dime Museum, which is now owned by Bruce Wayne, to avoid the Bat-Cave being discovered. Batman and Robin start operating the museum using their real objects while also trying to find evidence that could help them capture the criminal who wants to get in the cave. After extensive hours split between running the museum and investigating the criminal, Batman finds evidence to capture the crook just as the man manages to locate the cave. However, Alfred and Robin have managed to flood the cave by creating a dam on the underwater river. With the cave flooded, the crook decides to forget about the cave, but not before being captured by Batman. With the criminal caught, Batman and Robin begin moving the contents of the Dime Museum back to the Bat-Cave, and Commissioner Gordon is satisfied as the museum closes its doors for good.