Great 2-Character Movies 1930-70s?

I don't know who recommended "The Last Day of Summer" but thanks. I only gave it a 7.5/10, because there wasn't much meaningful dialogue, but I love movies along these lines.

-Man
-Woman
-Environment of their own

Maybe not entirely two characters but Woman of the Dunes comes to mind, you could perhaps argue Last Year At Marienbad as well.

No mention of Sleuth here? Or Same Time Next Year?