I had a very tough time when I trickled the ball into the little back bunker on Old Macdonald #6, the Long hole. Took me three to get out, with the third shot well played. Small but fierce little bastard pot bunker.
Thinking about it some more, other qualifiers at the Bandon resort include a back left bunker on the Old Macdonald #7 hole, and the bunkers short and right (and way below) the 14th green at Pacific Dunes.