Fun thread! I have been fortunate to play many of the holes mentioned, and reading the posts and looking at the pictures brings back lots of great memories!
My personal favorite blind par 3 is the Dell at Lahinch. Is it a great hole? I don't know, but it sure is fun! I was playing a few holes at twilight one fine summer evening, and ran into a local gentleman out walking his dog. He caddied at Lahinch in his youth, and told me about the "caddies loop". One of the "holes", which I played, was from behind 9 green to the Dell green. It is about 160 yards, is also a blind shot, but you are hitting down into a gap between the dunes to the green. Then you get to walk back to the #6 tee and play The Dell again!
Blind par 4 approach shots - my favorite is also #14 at Cruden Bay. It is so quiet on that green and then you walk up the steps and hear the ocean as you stand on #15 tee - very cool.
Another blind approach on a par 4 that deserves a mention - #14 at North Berwick, the hole with the grand name of "Perfection". After a decent drive, it is not a long shot, there is one of those huge poles with a target on the top to indicate direction. You know you are hitting directly at the ocean, that fact makes it tough to make a full swing!
I am not a big fan of blind tee shots, but if you like them, Royal County Down is the place to go!
BB