Book excerpt: Have you ever seen a manhole cover with little glass circles in it and wondered why it was different from the others? Did you ever imagine that there were actually tunnels under the sidewalks? You'll be surprised to find out how many cities in Colorado had these tunnels. And they're still under our streets Those manhole covers imbedded with glass circles, many that have turned purple with age, allowed light into the tunnels below. The Tunnels Under Our Feet explores these tunnels, or what's left of them, with lively prose and interesting historical stories. Join the author on her dusty yet exciting adventures as she crawls through basements dodging spiderwebs looking for tunnel entrances, many of which are now fi lled in. But it's not hard to speculate where they go if you're diligent enough to follow the trail.