The Quarry is a 3 mile loop trail located near Madison, WI. The trail is primarily used for mountain biking.
Really unexpected find. I'm new to mountain biking and had a blast here. Read a sign that Mad City Dirt put up, those guys put a lot of work into this place. Pretty tough in my opinion, but there's something for everyone.
Don't try to hike here - more of a druggy trsash dump than anything (syringes and beer cans everywhere).