The problem with long par-3s is that the emphasis on length makes it easy to forget about strategy, yet for most real golfers they play like par 3.5s and so should offer really good options, where as for pros they are merely 2-irons or the occasional 4-wood.
I'm surprised no one mentioned some classic Ross par-3s that must have been unimaginable killers in an era of hickory shafts, suspect golf balls, and small wooden heads. Try the following out (approx. yardages), all built before 1927:
-4th at Worcester CC - 235 yeards to a plateau green
-12th at Hyde Park G&CC, Cincinnati - 225 across a double ravine to a plateau
-9th at Maketewah, Cincinnati - 225 across a huge ravine
-14th at Scioto, Ohio - 220, uphill, sharply bunkered on the right
-17th at Brae Burn, Mass. - 255, downhill, to a low-slung green
-3rd at CC of Waterbury, Conn. - 230, downhill
-4th at Essex County Club, Mass. - 235, with a brook down the left and huge bunkers on both sides
-13th at Wampanoag, Conn. - 225, with a massive cross bunker 80 yads short and a slong upslope in front of the green