05/02/2012 02:40 pm ET

'Dark Knight' Trailer Unlocked With Batman Graffiti Hidden Across Chicago (VIDEO)

If you've seen the new trailer for "The Dark Night Rises" online without having to solve any puzzles first, you may have some sharp-eyed Chicagoans to thank.

Before the third teaser trailer for the newest installment of the Batman saga was released online Monday, eager fans across Chicago and other cities were asked to earn it--with a viral marketing campaign that took participants all across the city.

The film's official website posted addresses (many of which were key local landmarks) where Batman imagery had been chalked, and asked participants to submit photos to "the Gotham Police"--via email account, to unlock segments of the trailer.

The scavenger hunt was part of a larger viral marketing campaign that included an eight-page "police report" and fake newspapers calling for Batman's arrest.

Here's a rundown of where the Batman graffiti's been spotted. Have you caught sight of any? Tell us in the comments.

  • The Art Institute, 111 S. Michigan Ave.
  • The Pritzker Pavilion, 201 E. Randolph St.
  • The Congress Plaza Hotel, 520 S. Michigan Ave.
  • The Tribune Building, 435 N. Michigan Ave.
  • City Hall, 121 N. LaSalle St.
  • Union Station, 225 S. Canal St.
  • General Parking, 29 N. Lower Wacker Dr.
  • The Sears Tower, 233 S. Wacker Dr.
  • Wrigley Field, 1060 W. Addison St.
  • Belmont CTA Station, 949 W. Belmont Ave.