Originally a book by
Alistair Maclean, about a group of
WWII undercover agents parachute onto a high mountain containing a castle which is a major german HQ ("
The Eagles' Nest") -- and the only way in is via a cable car.
The book is filled with mystery and suspense, and, like many Alistair Maclean books, has also been made into a movie -- unfortunately, the movie features the main characters (especially Smith) as people who are trying to kill as many Germans as possible whereas the book describes them as conservative, only killing where absolutely necessary, if at all. Much of the story can also be seen in the Iron Maiden song of the same name.