Planning a scavenger hunt/tour

One of my projects at the UGLi this summer is to create some sort of tour of the library for the Great Indoors, an open house held in the library for freshmen during welcome week. The Great Indoors traditionally involves free pizza and provides fun activities that help students get comfortable with the library.

I've been scratching my head to come up with ideas for a tour that will be engaging and will help students learn about the library without the activity feeling like a chore. I think I've settled on creating a scavenger hunt, in which students follow clues that lead them to different parts of the library. I think something active will be more well-received and ultimately more useful for students, but I have yet to figure out exactly how to implement this idea.

So far I have a list of places I want to be stops on the tour/hunt. I'm trying to think of a theme, and decide what the clues will be. Some ideas we've come up with so far: crossword puzzles, word finds and photos of the next location. Originally, this tour was going to just be a Flickr photoset of the library, but I think the scavenger hunt has much more potential to actually be fun and interesting for incoming students.

Has anyone ever planned and created a scavenger hunt or active tour before? Got any suggestions? Send them my way.