The phrase "rolling dunes" refers to hills of sand in a desert or coastal area that have a smooth and curving shape, as if they are continuously moving or "rolling." Full definition
This secluded beach has a ribbon of golden sand and is flanked by rolling dunes. (loveholidays.com)
Watch as the terrain changes into rolling dunes, and arrive at your romantic dinner setting, nestled in the sand. (qatar-travelguide.com)
The one thing we can't find at El Mirage are proper rolling dunes, so we scout the small, sandy speedbumps that line the lakebed for potential air - worthy candidates. (evo.co.uk)