This is where my time is going now. Flight Simulator airports are generic and boring. Just the same buildings over and over again whether it's in Turkey or the back woods of Colorado, and there's no place to go with a sea plane. Sure, you can land on the water. Big deal. Eventually you begin to ask yourself why.
I used what I guess you would call a type of cad draw program to create this destination. This is my first attempt, a sawmill on the Chandalar River in Alaska. The program, called FSDS, was fairly popular up through FS9, and there were quite a few of us in the Flight Sim community uploading freeware to the net. But in the last and final update, FSX closed off the community from tinkering with the program (how you talked about modding games). It can be done, but it's much harder. As a result many people have uninstalled FSX and gone back to FS9, and most of the user designed stuff, especially scenery, is still devoted to FS9.
FSDS has been "updated" (kind of) to work in FSX, but the cad draw program is pretty hinky and a lot of problems have to be corrected by trial error, and it starts getting especially glitchy with Windows 7. I had to go to the Net and find some workarounds.
I've created 5 more of these destinations around Fairbanks, Alaska so far. The old uploaders of scenery seem to be gone now. I used to communicate with a bunch of them. I think they got discouraged by Microsoft making the flight simulator less open. I'm not sure if I'll upload stuff again. I may just make the stuff for my personal use.