While we may be nearing the end of Winterfest 2019, there are still daily challenges in Fortnite. The Ice Throne is one of the locations you may need to know to complete today's challenge. As part of the challenge, you need to search ammo boxes at the Ice Throne, Workshop, or Shiver Inn. You just need to search two ammo boxes and you can do it at any of the three locations.
You can find the Ice Throne north of Pleasant Park, marked on the map above. It is a massive structure made of ice, so it is hard to miss. There's a flat platform halfway up that you can land on if you want, and it's filled with small rooms and stairs that hold ammo boxes and chests to loot.
It's also quite a busy place right now, with lots of players wanting to check it out and explore it for themselves. As such, be careful as a few firefights are pretty much guaranteed if you go check them out now.
If you need help with any of the other Winterfest challenges, you can find guides for them linked below. You have until January 7 to complete them and get your free holiday loot.