A replica of the legendary 'Nazi gold train' is being built in Poland.
It's believed the Nazis filled a train with 300 tonnes of gold, jewellery and art. It was then driven into a hidden tunnel and buried in a part of Germany that is now in Poland.
However the train's existence has never been proven and it has never been found.
Around 15km from the current search site there is a replica being built.
So far they've built a 12m long armoured wagon which is being painted to look authentic. An armoured locomotive and three freight cars will be built next.
It's hoped the train will revive tourism in the area once it has been built.
In August this year it was revealed that two treasure hunters had made a start on digging for the train.
It's understood that if the train is found and there is gold on board it could be worth as much as £9 billion.
There is known to be a large network of tunnels in the area where they are digging but there has been some uncertainty surrounding whether they will actually find a train there.