There are plenty of quality bunkerless par 4s, but how many are there that don't use trees, elevation or "depressions that may as well be bunkers"? That would be a much smaller number, and I don't think I've seen any that qualify here that I'm familiar with other than Foxy.
So Doug, what you are basically saying is bunkerless par 4's that don't use any features other than plateau greens and half alpinised fairway ?
Niall
I was thinking of elevation not only in terms of plateau greens, but even moreso in elevation changes for the hole. A strongly uphill par 4 with a skyline green, for example, throws people off even with distance measuring equipment because they're playing off an uphill lie that affects the trajectory of their shot, are prone to overestimate a following wind or underestimate a headwind, are less certain of their shot because they're unable to see much/any of the green surface, and so on. There's enough going on that bunkers are unnecessary.
The depressions I was talking about are basically grass bunkers. I suppose one can debate whether it is a "par 4 without bunkers" if it has grass bunkers, but people usually use the term "bunker" to refer to a sand filled hazard. Typically when I see them in a fairway they're filled with a rough, and I think that makes for a more difficult approach for better players than an actual bunker would (unless the approach is long and the lip is high) While most bogey players are deathly afraid of the sand, and are more than happy to land in a rough filled "bunker" instead. I don't know why we don't see more of them - maintenance is easier, and they tip the balance of the game a bit towards worse golfers at the expense of better golfers. Good golfers have enough going for them, there should be more features that test their game rather than those that test the games of poor players but are hardly noticed by good players.
Even if the grass bunker is simply a bunker like depression that is mown normally, it can be more of a hazard for good players. If balls don't always roll to the bottom you can get some really funny lies, and if balls do roll to the bottom the odds are good you'll be playing out of a divot (or at least it'll worry the better player he might so he'll steer clear of such a grass bunker/depression perhaps even moreso than a sand bunker)