for a British Ocean's-11 style heist caper,

but if there are any screenwriters out there watching this:

I feel like this one might be for you.

British coins have the year that they were manufactured right on them.

So if you're a coin collector, and your dream is the full set,

it's not just a case of finding one of each design:

you also want each value from each year.

But in 1933, Britain didn't need any more pennies.

There were plenty in circulation,

so the Royal Mint, who make - or "mint" - coins,

decided they wouldn't make any one-pence coins that year.

That's not unusual, it had happened before.

Trouble is, King George V needed some.

It was tradition for the King to bury a full set of new coins from that year

in the foundations of new and important buildings as they were constructed,

and you couldn't use old coins for that.

So the Royal Mint did make some 1933 pennies.

No-one actually kept the records

of how many there were, but it was probably...

seven.

Which means that while the face value of those seven coins is a penny,

they're so rare that the price at auction these days

is easily more than £100,000.

And over at a London coin dealership, I got to see one of them.

- This is from a private collection,

one that's been loaned to us very kindly.

It's great because it's such an iconic coin,

we get a lot of visitors coming to see it.

Usually these coins disappear into safes and they're never seen again.

The last sold in 2016 for a hammer price of around £140,000.

It's the first time one's been sold for many, many years

and one would imagine, if it was to come on the market again,

it would sell for even higher.

- So there are probably seven 1933 pennies.

Three are in private collections I got to film one of those.  

Two are in museums. And the others...  

...well, that's the possible heist movie.

Because remember, the king buried some of the coins.

One of them was buried under this church in Middleton, West Yorkshire.

I say "was" because in 1970, it was stolen.

Whereabouts still unknown, although presumably

if someone in Yorkshire finds a 1933 penny in their grandparents' coin collection,

there'll be a bit of suspicion. And after this theft...

...the local bishop ordered that the coins under this church

should be dug up and sold

in order to prevent them falling into the hands of thieves.

That's one of the pennies that's in private hands legally now.

Which means there is one building and one buried coin left.

The last 1933 penny is buried somewhere under the foundations of Senate House,

at the University of London.

Or at least, everyone thinks it is.

No-one's checked since 1933, you'd have to dig it up.

And I doubt anyone actually knows exactly where it's buried,

unless they've done a huge amount of research and found some original blueprints.

Which, to be clear, I haven't. And besides, according to the university,

the whole package is buried very deep, not exactly where you'd expect,

which does sound like what someone would write

if they were trying to discourage amateur treasure-hunting thieves.

But Senate House is right here, in the middle of London.

There is some construction around here today,

a few people in high-viz jackets with power tools.

And while it's not exactly cracking the vault of a Las Vegas casino...

well, I don't have a plan for you.

And I don't recommend anyone try it for real.

But it is a heist movie waiting to happen.

Seriously, don't try it. This isn't the movies. It's... it's just a coin.

I don't have any plans to...

How do I make this sound not sarcastic?