Checkerboard Mesa: Zion National Park, September 2001 Our next activity was to drive along the Zion–Mount Carmel Highway. A portion of the highway passes through a 1.1-mile long tunnel that was built in the 1920s. Alongside this road are some of the tallest sandstone cliffs in the world. Wind and water cut perpendicular grooves into the surface of the sandstone of Checkerboard Mesa. (via Robby Edwards’ Photos)