Digital Fortress code (aka "Ultimate Code")
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What enigmatic sculpture stands one degree north of the location indicated in the code?
OK, this was actually by far the hardest question in the whole bloody thing. First things first, find the code...
It's next to comment #4 on the back cover. Get it the right way round (by looking at it in a mirror) and it reveals:
37 degrees 57 minutes 6.5 seconds North 77 degrees 8 minutes 44 seconds West.
If you add a degree north and Google that, about the second entry should be a listing for abcnews. Hit that link and you should get a page not found error. This is what stumped the hell out of me. However, using Google's handy dandy cache facility it brings the page up. With a little ingenuity, it turns out the answer is Kryptos.
UPDATE 22/02/2004: it seems the abcnews.com page I was linking to has disappeared off the face of the web. So instead look at this - Elonka's Kryptos page.
Onwards to code 2...