Tehachapi Loop, California

The Tehachapi Loop is part of the Southern Pacific/Santa Fe rail line that goes through the Tehachapi area. Due to the steep grade, railway engineers building the track in the 1870's made a 0.73-mile long loop, where the track makes a full circle to gain altitude. A 4,000-foot train crosses 77 feet above its rear cars in the tunnel below. Watching the trains loop over themselves is a tremendously popular attraction for railway enthusiasts (railfans).