A unit has "high altitude training" and I don't know why

[iamdanno]

If Mt Killi is in your borders be sure to not give open borders. You might be giving an advantage to a future backstabber......

I would say "In general, don't give open borders to anyone."

 

[Browd]

^^ I wonder what happens if the Inca get this promotion.

Every Incan unit can cross 4 hills in a single turn. Only advantage scouts have is crossing rivers and flat terrain with forest or jungle.

Attached is an Incan save (Standard Deity Highlands map) with Kilimanjaro close by. Start seems fun. Run your warrior and initial scout past the wonder, and they'll fly around the map snarfing up the ruins.