Yukon was intentionally designed to be harder for Engineers:
This abandoned mountaintop coalmine was repurposed by shadowy operatives into a top secret surveillance outpost—one which also, so nobody gets wise, insidiously continues to mine coal. There is also a log hanging in the center of the map—possibly as an example to other logs. Logs that said too much.
Five control points promise a lot of momentum swings in this compact outdoor map, with plenty of tunnels and rocky outcroppings. Plenty of alternate routes ensure that if you can’t get past a well-placed engineer through one tunnel, you might be able to sneak up behind them through another.
CP_Yukon is a community map from the brilliant dual-powered brain trust of Patrick “MangyCarface” Mulholland and Joachim “Acegikmo” Holmér.
-- Classless Update, Day 3
Point 1
Point 1 is extremely poor for defending as Engineer.
If you're building full size sentries, it may be better to build them down in the pit, although that means a Spy can back-cap the point.
Point 2
Point 2 has a few defense spots. One of the best for actually covering the point is at your team's end of the hall when you first come out the door from point 1. You had better have the Wrangler, though, or a sniper at the far end of the can easily take you out.
Another point is past point 2, on the middle route. You can place a sentry on the walkway up. The problem is that, if you place is close enough to the point to be able to see it, it's far enough from the point 3 area for Demomen to be able to take it out.
Point 3
Thanks to point 3 being moved, your best bet is near the point itself, preferably where the fence covers it, so it can't be shot by Snipers (or at least where you can't be shot by Snipers). Your biggest problem here is people sneaking up behind you. You could place it at the very end of the point 3 bridge, facing the point to help counteract that.
Point 4
Building slightly to the enemy's side of point 4 works pretty well, as it covers both entrances to the point 4 area.
Another Alternative
Due to the difficultly in guarding points with a level 3 gun on this map, Mini-sentries work fairly well on it, at least when combined with the Frontier Justice.
There are quite a few possible locations. The ones I know of include:
- The shack between BLU spawn and point A (left side from BLU), lower level.
- The shack between BLU spawn and point A (right side from BLU), upper level.
- The little dead-end near point A.
- Right in front of point A.
- On top of the rocky cliff between points A and B.
- The little shack between points A and B.
- Right in front of point B.
- The balcony near point B where RED initially has a drop down to point A.
- The other balcony near point B.
- The upstairs room across from RED's upper spawn door near point C.
- The downstairs room across from RED's lower spawn door near point C.
- The library room inside the Manor (left from RED spawn).
- The little dead-end room near point C.
As you might have guessed, there are a lot of different places it can spawn. Not only that, but unlike the Horsemann, it appears to have no bearing on which points are actively in play.
Being a Scout gives you an advantage to finding them, since you move faster.
Best Answer
Here's an image gallery with the gift locations on Eyeaduct.
The gifts that spawn in the underworld give Haunted versions of the same 2011 Halloween items. There's no special difference between Haunted and non-Haunted versions other than the item name and name color (Haunted items are purple, like unusuals).
According to commenters, gifts can always spawn in the underworld or on the main Eyeaduct map. Apparently there is a difference in the "gift has appeared" message between underworld and non-underworld gifts but I have yet to confirm what the difference actually is.