Carhenge is the reason most travellers know Alliance exists. Jim Reinders built the monument for the 1987 summer solstice, using old American cars set upright, stacked, and painted grey to mimic Stonehenge on the Nebraska plains.
It is free, quick to visit, and better than the joke sounds. The surrounding car-art pieces and open prairie setting make it one of the more memorable roadside stops in the Great Plains.