The coins have been dubbed the 'holy grail' of change collecting and if you find one it could be worth a lot more than 20p ...

An unusual coin could net its owner over 250 times its face value after an error when it was made. The rare 20p coin was one of an unknown number released by the Royal Mint without a date.

Cryptocurrencies can be used as a store of value, unit of account and medium of exchange. These digital assets are secured on a distributed ledger called the “blockchain.” The first ...