biking in abandoned turnpike tunnels

Here's a fun thing to do if you have a Saturday free and live anywhere near the Breezewood exit on the PA Turnpike: Bike through some abandoned tunnels! Apparently they re-routed part of the turnpike awhile back, and it left a couple of the tunnels abandoned. They're planning to make it into a complete loop that you can ride, with a trail-head and whatnot, but for now you're allowed to enter at your own risk. It's a pretty neat experience, feels kind of post-apocalyptic to say the least.