We used to live a few miles from Torrey Pines and Del Mar, and walked on the beach there fairly often. As they erode, the cliffs above the sand supply the beach with cobblestones. Depending on the season and recent surf energy, the beach ranges from nearly stone-free to being so covered with cobblestones as to nearly hide the sand below entirely. Here is a typical sunset along the long, beautiful stretch of beach from Del Mar south to Torrey Pines, with cobblestones.
Sunset, cobblestones, surf and sand, Torrey Pines State Beach.
Image ID: 05518
Location: Torrey Pines State Reserve, San Diego, California, USA