Our first stop is at Fajada Butte, an isolated mesa which rises to height of 135 meters. Near the top on the south side are three stone slabs two to three meters high and weighing about 1000 kg. The slabs lean against the cliff. They direct sunlight to two petroglyph spirals behind them.At noon on the equinox and solstice a vertical shaft of light intersects the spirals marking the solar event. This phenomenon was discovered in 1977 by artist Anna Sofaer.