Yep. The high areas extend out from the forest, ending about where that lower-left city is. The eastern part of the 'U' then flows down into the old subduction valley.

I probably ought to give some thought to seismic activity, but I don't anticipate the campaign taking much longer than a couple of years in game time. I may package the world info for distribution when I'm done with it, though, so I may need to revisit the matter some day.

Navigation in that area might have been difficult long ago, but nowadays it's pretty densely settled, with a well-developed and maintained road network.

Stay tuned for a more detailed map of that part of the world--As soon as the new City Designer is released I'm going to try an interesting map of the Imperial City and environs.