Tim persuades Brenda to go up with him for her first ever flight. Below, they are above Treasure Island (map), newly built on silt dredged from the Bay in 1936 to host the Golden Gate International Exposition, a World's Fair celebrating, in part, the opening of the Bay Area's two great bridges. The movie was filmed during the fair (1939 -1940) and the island is packed with Exposition buildings. The elevated approach from Oakland to the eastern section of the Bay Bridge is visible at far right.
Then ... Brenda is tense and white-knuckled as her relaxed guide points out the Tower of the Sun, the Exposition's 400 foot tall centerpiece.
... in 1939 ... this contemporaneous image gives us a closer look at the Tower Of The Sun. The theme of the Exposition was 'Pageant Of The Pacific' highlighting the culture and architecture of the countries surrounding the Pacific Ocean. As an example the colossal Elephant Towers flanking the approach to the Tower Of The Sun incorporated both Oriental and Mayan elements. Check out the informative newsreel footage here and chuckle at the stridently hyperbolic commentary so popular at that time.
This wider view shows the full expanse of the Exposition and the entire eastern section of the Bay Bridge can be seen, connecting to Yerba Buena Island on the right.
... and Now, the same aerial view today courtesy of Google Earth. The original cantilever bridge is partially dismantled after been replaced in September 2013 by a new causeway and single tower suspension bridge.
Then ... The sightseeing flight continues across the Bay to San Francisco. In this shot the clock tower of the Ferry Building is dead center on the Embarcadero - beyond it is the western section of the Bay Bridge.
... and Now, the bridge and Ferry Building remain the same but over 60 years of rampant development has transformed the Financial District.
Then ... They swing back across the Bay and Brenda is brought down to earth, so to speak, at the sight of Alcatraz below them. She is yet to reveal her past to Tim who doesn't know she has a husband nor that he is incarcerated on The Rock.
... and Now, the prison block itself is unchanged (other than closing down in 1963) but a close comparison of the Then and Now images does reveal some additions and subtractions on the island.