The skywalk in downtown Des Moines is over 4 miles long. Now that I've started working downtown again, I've gone back to exploring the skywalk and seeing what it has to offer. Your mission, if you choose to accept it, is to find each of the pictures below and use what you find to determine the final coordinates. I've deliberately left out some details about these locations so as not to give too much away, but if you're not familiar, I encourage you to check out the entire skywalk system.
All of the pictures are handicap accessible; I'm not sure about the final cache - it may be too tight a squeeze for a wheelchair. The terrain rating represents the distance you'll need to travel to find each of the clues. As with all downtown caches, going after the final may be best for weekends and evenings, when there are few muggles around.
The final coordinates are N 41° 35.AB9 W 093° 37.CD2
On the bottom corner of this mural is the artist's initials. Using a standard alphanumeric cipher (A=1, B=2, etc.), the first initial letter translates to A.
In one part of the skywalk, there are a series of informational circles like this one. (Note: this one wasn't chosen by accident.) Including this one, how many total circles are there? B = the total number of circles minus five.
Once you find what's shown in this picture, continue walking. On your right, you'll see a series of office suites. The suite between #205 and #215 is Suite #2C0.
On this picture, you'll find a train. The three-digit number on that train is KLM. K+L-(2*M) = D.
Picture #5 (BONUS PICTURE):
While you don't technically need this one to determine the coordinates, once you get to the location of the final, you'll find it useful. Immediately under the year 1966 is the following number: 481X162342. What is X?