Why do you Americans always answer questions with questions of their own?
This seems to be a fairly well regarded little thriller. I am not sure why. I found the simple story of a tourist beguiled by a woman into freeing her husband slow and ponderous for the first 40 minutes. It livened after this but not by much, the plot twists are simple and well telegraphed and the whole film simply falls rather limp and flaccid.
Verdict: I wouldn't bother. There were far better films being made in 1963.