Thanks everyone. After adding a few ledges to the Dark Sea as well as adding a city in the lower left corner looking out on the Sea, I think my next 2 items up for grab are to add some semblance of cavern ceilings (along with stalactites) in a few places, especially over the two water bodies. Second, I was thinking of mapping out the Western Gate and it's tunnel leading to the main city in the center. I was thinking along the lines of some mountains fading in from right to left as well as perhaps some vegetation and a gate tower to the west of the city in the center. Not sure about the last one yet.. will have to play with it to see if I can get a nice style blending upper world elements with below ground elements.