A great beach proposal idea in san diego is to have a custom sand castle built in advance with your question etched on the side of the sand castle! Go for a walk on the beach and, “Oh, check out that sand castle!” I was visiting the Hotel Del on Saturday, and met “The Sand Castle Man” as he was working on his latest creation shown below. He has custom built several sand castles for marriage proposals in San Diego & Coronado and he had some fun proposal stories to share.