Photosynth
Double Arch, Arches National Park, Utah In a park with nearly 2,000 natural arches, this one stands out. In this high-desert landscape, arches formed as salt deposits dissolved, collapsing soft red sandstone into vertical slabs, whose centers eventually washed away. Send us your photos of the Double Arch. Once we have enough pictures (it takes about 300) we'll create a Photosynth.