Montara State Beach is just north of Half Moon Bay, CA, and offers one of Northern California's cleanest and most beautiful shorelines. The views are breathtaking, and during the winter months the waves tend to get really high. When we were there in January they were easily in the range of 15 feet. The beach is far enough from large towns to not be too crowded, but close enough for easy access to great restaurants and activity. Just don't forget to bring sandals—the sand here, while beautiful, is pretty course.