Trivia

The lighthouse in the film and its source novel was inspired by the real lighthouse at the island of Isla de los Estados in the Argentinian territory of the Tierra del Fuego Archipelago situated near Cape Horn.

The movie was a commercial failure at the international box office.

The lighthouse tower seen in the movie was built on location at Cap de Creus near Cadaqués, Catalonia. Cap de Creus is the easternmost point of Catalonia and therefore of the Iberian Peninsula. Despite being temporary, the tower would remain standing for many years. The work of a mason from Cadaqués, Pere Clavaguera, that lighthouse was not demolished until 1998, although there were voices that demanded its conservation. In the place where it had been erected, the City Council of Cadaqués placed a commemorative plaque.

The project was re-activated in the late 1960s by Bryna, Kirk Douglas' production company. Douglas hired Kevin Billington to direct in March 1970. Douglas did it as a co-production with Alexander Salkyind's Vulkano Productions. National General Pictures agreed to distribute. Finance was mostly raised from a bank in Spain. It involved people from France, Spain and Italy. Billington said "there are about twenty-three co-production deals; there are problems about casting and about language." Douglas said he was paid "a lot of money," estimated at being US $1 million.

The picture's second failed attempt at production was announced in an article published in the July 1965 edition of show-business trade-paper 'The Hollywood Reporter'. Principal photography was scheduled to commence in early 1966 in Malta and Portugal under the direction of Andrew V. McLaglen. The Columbia Pictures production was to be produced by Charles H. Schneer from a screenplay by scribes Beverley Cross and James Edward Grant.