A giant 220-pound solid gold coin worth around $4.5 million was stolen from the Bode Museum in Berlin Monday, according to the New York Times. Nicknamed the “Big Maple Leaf” for its picture of the Canadian national symbol on its back, the coin measures 1.2 inches thick with a diameter of 20.9 inches, making it the largest gold coin in the world.

Police believe at least two thieves used a ladder to climb through a window from a neighboring elevated railway bed and then carted the coin off in a wheelbarrow, according to the Associated Press. The theft involved smashing protective bulletproof glass and lugging the heavy coin through the museum and up a flight of stairs to the window. Since it will be nearly impossible to resell such a unique and highly publicized coin, investigators say it will likely be melted down and sold off on the open market.

The Royal Canadian Mint issued the coin in 2007, giving it a face value of $1 million Canadian, which calculates to about $750,000 U.S., but it’s actually worth quite a bit more based on the current market price of gold. Only four others have been minted to date. The coin had been on loan to the museum from a private collection since 2010.