Map: A little artisanal map... with 1225 provinces

[jfp3]

Hail Gents,

I just started a game on this map a few nights ago and have yet to figure out how to get a force to enter caverns. I have force at one end, left click normally to move to proper cavern province, but no corresponding line indicating a move shows up, nor does my unit indicate a "move" pending.

Is there something I'm missing to venture into the Caverns from the main surface? Help! I want to emerge at an unsuspecting nemesis' BBQ unannounced :-)

BTW...amazing map. Just amazing. Reminds me a bit of the old "Empire of the Fading Suns" game maps.