Referred to as "monoliths", these sheet metal structures began to be constructed in the wake of the discovery of the Utah monolith, a 3 m (9.8 ft)-tall pillar made of metal sheets riveted into a triangular prism, placed in a red sandstone slot canyon in northern San Juan County, Utah.

What is the monolith and where did it come from?

The Utah monolith was a metal pillar that stood in a red sandstone slot canyon in northern San Juan County, Utah. The pillar was 3 m (9.8 ft) tall and made of metal sheets riveted into a triangular prism.

How monolith is formed?

A monolith is a geological feature consisting of a single massive stone or rock, such as some mountains. Erosion usually exposes the geological formations, which are often made of very hard and solid igneous or metamorphic rock. Some monoliths are volcanic plugs, solidified lava filling the vent of an extinct volcano.