### The Wave
USA (Arizona) — It looks like a giant, neon-striped skate park, but it's actually the fossilized remains of a 190-million-year-old desert.
When you step into The Wave, your brain screams that someone tilted the earth or carved a massive, sweeping skate park out of striped rock. But there was no tectonic lifting or tilting involved. You are actually looking at the frozen ghosts of giant sand dunes from 190 million years ago, during the Jurassic period. Back then, this part of Arizona was a massive desert larger than the modern Sahara.
The mind-bending lines are the result of a process called aeolian cross-bedding. Ancient winds blew massive dunes across the desert, and sand slumped down the steep, sliding edges (the slip faces) of those dunes. Over millions of years, these rhythmic layers of falling sand stacked up, got buried, and slowly turned into solid Navajo Sandstone.
The wild colors come from "diagenetic coloration." Groundwater packed with iron oxide minerals (like hematite and goethite) bled through the porous stone, permanently "rusting" the sand layers into brilliant bands of salmon, yellow, orange, and purple. Finally, seeping water and funneling winds scoured the rock, polishing it into a U-shape. The rock looks perfectly designed, but it's just ancient wind, deep rust, and an awful lot of time.