It goes to the Eastern Low Lands if I remember my Courthan Geography correctly. Didn't get there in 1.0 myself but Moose Sensei did talk about the maps of 1.0 vs the maps of 2.0 where Courthas was mentioned.

If I'm right about the low Lands then Griffin Crossing eventually leads to Xelphatol which seperates Courthas from Gyr Abania and by extension Ala Mihgo.