Jack Grey is a news correspondent for the British Broadcasting Corporation.
Wales last played in a football World Cup 64 years ago, and a win later will put them in a position to return.
One of the most important games in decades is being played in Wales by fans from across the world.
They were eliminated by Brazil in the quarter-finals in 1958, with the winner being Pele.
If they win against Austria tonight, they will face either Scotland or Ukraine in the next stage of qualification for the World Cup.
Fans have been arriving in the capital since the early morning for the game.
The chief executive of the Football Association of Wales said it was a big game.
It is a World Cup final for us.
He said that it was up to the players after they crossed the white line.
They have brought a lot of joy, a lot of honour and a lot of pride to Wales and would cement their place in folklore.
I have no doubt that the guys will put on a great performance for their country.
Fans from all over Wales and the world are making the journey to Cardiff, with one going from Tokyo to Japan in 24 hours.
Bale said this would be his last chance to play for Wales at a World Cup.
Wales qualified for their first international tournament since 1958 at the European Championships, an experience which Bale said can inspire the team to qualify for the World Cup.
He said that they have to give 100% and have no regrets.
We can draw on past experiences that have hurt us but also the excitement of what potentially is ahead, so there is a lot to play for.
TfW warned of delays for people travelling via train, and said face- coverings were mandatory on public transport.
Due to the late kick-off, services after the match will be extremely limited.
Leckwith Road will be closed after the match, with buses diverted.