Universe unveiled on Instagram: "The Grand Canyon in Arizona, USA is one of the most breathtaking natural wonders on Earth — a result of millions of years of geological activity and erosion by the Colorado River. Around 5 to 6 million years ago, the Colorado River began cutting its way through layers of sedimentary rock — limestone, sandstone, and shale — that had been laid down over nearly 2 billion years. As the river flowed, water, wind, and ice slowly eroded the rock, deepening and widening