Actually I was thinking of the comments regarding Gamble Sands, so there.
As for where I'm going, the most-difficult course to design must be one that's easy yet interesting, yes? In which case I'm curious how to do that. I would guess the easy way to do that is to make it short with roiling greens. But why don't we up the challenge from there: what features enables a course to be easy yet interesting without necessarily being 5,000 yards long and / or Three Jack City?
Can it be done?
I would add that I'm interested in how you would do it if starting
today. Do old courses changed utterly by technology (I&B + agronomy) even count -- or are those just happy accidents?
Now that you've insisted on revealing our destination, it's your responsibility to make the drive interesting. You're on the clock, get going.