The International Rugby Board has confirmed that the North v South clash of the rugby hemispheres will take place at Twickenham on 30 November.
The Millennium Stadium bid for the game when the fixture was initially put out to tender, but the IRB have now opted to go to London for the inaugural fixture.
"The match was put out to tender, and the WRU duly submitted a bid. It was never at any stage formally agreed that it would be in Cardiff, and we're obviously disappointed to have missed out on this occasion," said WRU media manager Lyn Davies.
South Africa's Andre Watson has already been named as the referee for the game and the IRB will shortly announce a match sponsor and TV broadcaster.
Set to become a biennial event in the rugby calendar, the proceeds will go towards the development of rugby in the smaller playing countries around the globe.
IRB chief executive Mike Miller claims there is "tremendous enthusiasm" for the game.
The IRB will also hold their Annual Awards ceremony in London on the same day as the game.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.