Mesquite Flat Sand Dunes, Death Valley National Park

Super hot, but fun to walk around in the sun on the sand. I would suggest wearing glasses so that you have some protection when the wind starts blowing sand everywhere. It would probably be easier to hike on the sand with sandals, rather than with hiking boots. If you're trying to go up a large sand dune you can kick your toes into the side and use the sand kind of like a step

This is one of the signature sights in the park and you can spend quite a bit of time there. This place does get quite busy so get there very early or late in the day to avoid the crowds. You can go ahead walk for what seems like forever as the dunes go on and on. This is a great spot to watch both the sunrise and sunset.