Hidden inside the sparkling halls of the Barclays Bank building is this little museum dedicated to all things money. It starts out by detailing the ancient forms of currency used millennia ago such as whale teeth and shells, before moving onto coins, paper money and the evolution of modern banking and ends with a look at the 2008 global financial crisis. As well as Roman coins and bank notes from across the world, the museum also boasts other curiosities such as a massive 19th-Century calculator and some old-fashioned piggy banks. To enter you must show a valid form of ID (passport or driver's licence) at reception and wait for a member of security to accompany you up to the museum.