IMDb reports that the majority of the film's shooting locations were in Austria. The film's opening title showcasing beautiful snowy mountains was filmed in Saalfelden, Austria. The Schloss Adler, the mountaintop fortress the soldiers raid, was filmed at the Burg Hohenwerfen Castle in Werfen, Austria. According to Republic World, the stunning location is free and open to the public, operating today as a museum and falconry center. Werfen was also where the train station and high alpine huts featured in the film were shot. The location was used in other films, most notably the classic musical hit, "The Sound of Music" (per IMDb). In "Eagles," the scenes using the cable car that helped bring them to the castle were shot at the Feuerkogel Mountain Lift in Ebensee, Austria. Any scenes featuring both the cable car and castle together were shot using a scale model.
Other Austrian locations in the film include Lofer and Aigen im Ennstal, where most of the village and airfield scenes were shot. According to Otakukart, shooting in Austria took place throughout late winter to early spring of 1968. Varying harsh weather conditions and Richard Burton's binge drinking led to numerous filming delays.
