However, a train station doesn't have this problem - if there is a valley in the middle of the area buildonslopes fills it automatically.
The screenies explain it much better:
1: you can't build an airport accross this valley
2: you can build the airport on the edge of the valley
3: you can build a train station over the valley
4: you can't build an aitport over a hole either
5. but yuo can build a train station
would it be possible to enable airports to be built like train stations?
Chris