Two of San Luis Obispo County's nicest nude beaches are very near Pismo Beach.
Popular with locals, the Cayucos beach is wide, sandy and fairly flat, with a pretty pier in the middle. It's a good place for sand play, with lifeguards on duty in the summer and an outdoor shower in case of big messes. It's right in the middle of town so you can find food and drink without going far.
Follow Embarcadero Road along the waterfront toward Morro Rock or take the trolley to reach this multi-facted area. There's a skateboard park and small playground for the kids, good fishing and sea otter-watching off the rocky shore and a nice sandy beach opposite, where you can surf (or watch) and play in the sand. The link above takes you to a map.
Better known for the cozy hotels that line the road nearby, Moonstone Beach has a little of everything: an easy clifftop boardwalk that's easily accessible by wheelchair or ECV, tidepools, surfers, crashing waves and golden-colored cliffs above the rocks. There's also a restaurant right across the road with a large outdoor deck. The link above takes you to a map.
These sand dunes provide a playground for off-highway enthusiasts and offer visitors a place to swim, surf, fish, camp and hike.
This state park has an ocean lagoon, is popular with bird watchers and is close to many conveniences in town.