To complement my list of high-detail airports and cities here

http://blogs.msdn.com/ptaylor/archive/2008/06/25/high-detail-feature-list-and-then-some.aspx

SimTours is a great place to know about. Check it out here

http://www.simtours.net/

Not only do they have places with custom objects, they also list places with "anomalies". Great stuff.

Happy flying!