In hidden vaults across the country, the US government is building a stockpile of $1 coins. The hoard has topped $1.1bn - imagine a stack of coins reaching almost seven times higher than the International Space Station - and the piles have grown so large the US Federal Reserve is running out of storage space.
Americans won't use the coins, preferring $1 notes. But the US keeps minting them anyway, and the Fed estimates it already has enough $1 coins to last the next . . .
Full story at: BBC News