I think if we had to narrow down the point of Athletics, it is to allow us to overcome barriers in travel. Basically its allows us to take shortcuts around obstacles, with enough skill. The Rivers from Xing to Haven and Xing to Leth (bypassing the ferries), along with the climbing under the gondola are perfect examples of this skill being executed nicely.

However, the skill has been very much neglected for a long time now. I think one of the best adds to date was the Segoltha finally being swim-able after a number of years of it being suggested (and that was probably 8-9 years ago).

Frankly, we need more bypasses, and for much higher levels. The Segoltha could probably have its difficulty increased. A few high level hunting areas could be expanded with a difficult (1300-1400 minimum) climb/swim to get to the expansion (coughvoidmothscough). But I feel like we could certainly use a few more obstacles around the realm to utilize athletics and shorten travels. So in that light...

Ideas:

Swim from Haven to Lang (1100+)
Swim from Rossman's to Lang (1000+)
Swim from Mriss to Merkresh (900+)
Swim from Merkresh to Hara (1500+)
Swim from Ratha to Asery (1500+)
Swim and Climb from Leth to Ain Ghazal (1600+)
Massive climbs from Wolf Clan to Boar Clan (1600+)
Swim from Taisgath to Ratha (1200+)
Climb to Expansion for Void Moths (1300+) (Personal favorite due to the crowded area of moths)
Climb to Expansion for X crowded hunting area (athletics slightly above combats needed for that area)
Climb to Bone Wyverns or ice Archons (1000+)
Big Ocean travel (1700+)

Side Note: Ranger Scouting could and probably should come into play a bit too, with Athletics.