Moreover have a river flow through the sand mountain if you flying on the sky and view it in the birdview that is so cool.
Minecraft PE seed : PLANET EARTH – Huge Sand Mountain
In this seed you spawn on the grass landscape biome, at the spawn you can see the small sand biome. This sand biome quite look like the other sand biome but have a point made you attention it. That is huge sand mountain, it so huge and look like that is the symbol of this seed, other sand mountains usually made by stone with sand blocks but this mountains mostly generated by sand.
Seeds : PLANET EARTH Work in PE ver0.10.0+