World Map Terrain is almost complete

I have built a world map terrain from a heightmap and so now I have a unity scene with a "life size" terrain of the entire world of A Signet Forever in the game. I have placed the oceans, cities, major sites, and most of the mountains and topographical features onto it. I have a working airship for the player to cruise around it and I've optimized it's properties so that it has what I feel is the proper amount of speed, turning speed, vertical speed, drag, angular drag, and so forth. Also, I am almost done setting up scene changers around the cities so that you enter the city when you collide into the city with the airship. I still have a few more programming tweaks to make for that to get it right. Then I still need to set up the warp areas on the north, south, east, and west borders of the world so that when you drive into the northern border, you reappear from the southern one, creating the illusion that you are circling the globe and coming around from the other side.