A truly unique Park City activity best known to longtime locals only. Drive up to the top of Iron Mountain Drive and carefully park in the few spots available on the side of the road. Hike up Iron Mountain Trail (pretty steep and invigorating; will take you about an hour) and then sled all the way down on a Swiss Bob - a little plastic sled that just covers your backside, basically. Use your feet to steer, and lean back or bail completely to slow down if a tree happens to get in your way. You can find Swiss Bob sleds at local sporting goods store Jans or Sports Authority.