The Bode Museum in Berlin, Germany is known for its collection of 540,000 rare coins. As of this week, however, it is down to 539,999. The collections largest coin has been stolen. The giant coin weighs 100 kilograms and is 53 centimeters wide. The Royal Canadian Mint produced the coin. It is known as Big Maple Leaf. The face value of the coin is $1 million. But experts say it may be worth up to $4 million because its gold is so pure. It was loaned to the museum in 2010. The museum kept the coin behind bulletproof glass. But, thieves managed to break the case. Berlin police believe the thieves climbed in through a window at the back of the museum. The window is next to train tracks. Police say the thieves used a ladder to reach the window, dropped into the museum, broke the case and took the coin. Since the coin was so large, police are looking for a group of suspects.