Stewart arrives in Iceland and waits for his contact in the cafeteria of the old Keflavík Airport Passenger Terminal.
The building served as the international air terminal from 1949 to 1987 when the current Leifur Eríksson terminal was completed. From 1951 it was in fact located in the middle of the Keflavík United States Military Base since both civilian and military air traffic shared airfield facilities. Following considerable interior changes and modifications it continued to serve in part as a terminal for US military flights in connection with the Iceland Defense Force and US Naval Air Station Keflavík until departure of these forces in 2006 (8th September 2006). 
The United States has had a military presence in Iceland since 1941, and a formal defense agreement with that nation since 1951. The Navy assumed the responsibility of running the air station from the U.S. Air Force in 1961. The base acted as a platform for several operational capabilities throughout World War II, the Cold War and in the modern arena. The hangar housed rotational P-3 Orion aircraft and crews in support of anti-submarine warfare until 2004. The Army National Guard units and Interim Marine Security Forces stormed the lava fields surrounding the base during training exercises such as Northern Viking. The flight line served as a launching point for U. S. Air Force F-15 fighters. 
The filming of the scenes in the cafeteria took place on 1st June 1978, an article appearing in Vísir newspaper on 2nd June 1978, which may be viewed here, reported on the filming.
Following the filming the interior of the building underwent a great deal of change, the cafeteria becoming a military courtroom. Lying to the south east of the Leifur Eríksson terminal the old terminal is scheduled for demolition. Included in the gallery images are some more interior and exterior images of the old terminal.
Images © BBC Scotland, © The Bagley Brief, © 1978 DV ehf. & © Google earth – Courtesy of Friðþor Eydal.
1. Eydal, F. (2013) pers. comm 1st March, 2013
2. America’s Navy (2006). Naval Air Station Keflavik Disestablishes After 45 Years (2006). [online]. URL [Accessed Jan. 3rd 2015]