Lost Horizon
Starring Peter Finch, Liv Ullmann, Sally Kellerman, George Kennedy, Michael York, Olivia Hussey, Bobby Van, James Shigeta, Charles Boyer, John Gielgud
It's a drama and musical movie, and has a rating of 5.2 out of 10 from Imdb which is fairly okay for this kind of movie.
Watch it here
Not found streaming from Belgium.