It's impossible to imagine San Francisco without certain landmarks.

What would the city be without curvy Lombard Street, luxurious Union Square or, gasp, the Golden Gate Bridge? But once upon a time, these now-iconic landmarks were in their infant stages. Take a crazy look back at some postcard views before they were famous.

This photo of Alcatraz was taken sometime between 1873 and 1880, long before it became a federal prison, in 1934, and home of the notorious Al Capone and the Birdman of Alcatraz. (via Wikimedia)