It's 2fort with a little bit of snow and festive trimming. The pictures really don't do it justice. Entire sections of the map have been redesigned/scrapped. Yard is now super important, and the cramped easily campable intel room is gone. It still has plenty of issues, but I almost want to say it's better than stock 2fort.
Definitely a very pretty map with an aesthetic you don't really see in TF2 while not being buckawfully ugly. I'm not entirely sure how well it'll play out, but it has some interesting bits. The path from spawn to mid is unintuitive at first, but it's not that bad after a couple of minutes, and it has plenty of flanks/weird routes from one place to another. The point being over a chasm should provide plenty of opportunities for people to get dumped into the pit, and it should keep the Heroes away from the point.
Maybe not one for rotation, but definitely worth a trial run one night.
Another one that used to be in rotation and seasonally appropriate.