May I ask, where is that terrain located in particular?
well, the excat geographical location apparently is a secret, but it was made by DiFis (who now moved on to BOS, i think..) and it is available in the Quick Missions under "Fantasy Island".. It has many fun landing places and is also quite comon on the fast-action MP servers.
The most challenging parking place is by the castle.. that really takes some time to get used to and it is best done in the Fokker DVIII due to the needed clearance of the wings to the ground on takeoff: