When: Saturday, June 26, 17:00 BST
How to watch: BBC One
The Johan Cruyff Arena in Amsterdam will play host to the first last-16 game at Euro 2020.
For Wales, this is nothing new. Rob Page's side reached this stage five years ago on their memorable journey to the semi-final.
Denmark, on the other hand, haven't progressed past the group stage at the European Championships since 2004.
However, with the Danes fuelled by emotions - following the Christian Eriksen incident - they became the first team in the competition's history to reach the knockout stage after losing their first two group games.
What's more, Denmark have won their last three competitive encounters against Wales. Considering the high they're on, it's no surprise to see them priced as the 3/4 favourites.
Last three matches
Wales 1-2 Denmark (UEFA Nations League - November 16, 2018)
The last meeting between the two nations took place during the 2018/19 UEFA Nations League campaign.
This was the final game in Group Four and the stakes were high as the winners would be promoted to League A.
Denmark took a first-half lead when Nicolai Jorgensen bagged the opener in the 42nd minute.
Wales looked for a response but in spite of their numerous goal attempts, they lacked quality in their finishing.
Denmark's Martin Braithwaite then punished the Dragons with a second goal for his side in the 88th minute.
Gareth Bale gave Wales late hope with a goal of his own just a minute later. Ultimately though, it was Denmark who celebrated promotion.
Denmark 2-0 Wales (UEFA Nations League - September 9, 2018)
Their earlier clash in the UEFA Nations League followed a similar path.
Christian Eriksen opened the scoring in the 32nd minute before adding a second from the penalty spot after the break.
This proved to be a very disappointing outing for the Welsh who only managed one solitary shot on target.
Denmark 0-1 Wales (Friendly - November 19, 2008)
Craig Bellamy scored the only goal of the game in Wales' last victory over Denmark.
The likes of Chris Gunter, Gareth Bale and Aaron Ramsey were all involved as Wales left Copenhagen with a confidence-boosting win.
Last ten head-to-heads
Wales wins: 4
Denmark wins: 6
Wales goals: 9
Denmark goals: 12
Wales not easy to crack
One impressive fact about this Welsh team is that they don't lose many games.
Out of their last 22 international outings, Rob Page's side have only suffered defeat on four occasions.
The last of those said a lot about the character of this Welsh side. Italy, who are one of the tournament favourites, only managed to score once. That's despite the fact that Wales went down to ten men following Ethan Ampadu's red card.
Another good omen for the Welsh is that they haven't lost consecutive games in two years. Those stats certainly make good reading ahead of the nations biggest game in five years.
The world supports Denmark
Denmark are without a doubt the story of Euro 2020.
Following Christian Eriksen's collapse, the world watched on and supported the Danes as they miraculously booked a place in the last-16 stage.
After losing to Finland in their tournament opener, Denmark showed a lot of bravery in their second group game against Belgium. Ultimately, though, they lost 2-1 to a high-quality opponent.
Nevertheless, they certainly turned on the style in their final group game. A 4-1 thrashing of Russia saw them book their date with Wales and continue their incredible story.
Without Welsh supporters in Amsterdam, the majority of the stadium will be backing the Danes. But then again, Wales have already come up against hostile atmospheres in this tournament and managed to prevail.
Aaron Ramsey has one goal to his name after bagging the opener against Turkey last week.
But in truth, the Juventus man could have been among the tournament's top scorers considering the number of opportunities he has had.
The Bale-Ramsey combination will have to be at its best if Wales are to progress. With that in mind, it may be worth backing the former Arsenal man to score anytime at 11/2.
If you're looking to go with someone from the Danish camp, back Yussuf Poulsen at 21/10. Poulsen already has two goals to his name and looks a threat in the attacking department.