Driving into Great Sands National Park can be a disorienting experience. Hallucinatory experience may be more accurate. The road is pin straight, so everything slowly gains depth and weight as you approach. I’ve encountered this many times with mountains or large bodies of water. But in those cases your brain has a multitude of reference points. You know what a mountain looks like from a distance and can process how it will expand as you draw closer. Same reference points for water. It all falls apart for sand. There are few psychological reference points when something is unique – and the Great Sand Dunes are certainly unique. As you get closer, your brain has a difficult time processing that the smooth, undulating mountains ahead are made of sand. Trust me, it takes a while to realize what you are looking at. And even then you begin to doubt your senses.