San Diego Sand Castles offers three-hour classes that teach customers how to build the perfect sand castle on a San Diego beachIf you’ve walked by Dog Beach in Del Mar recently, you may have noticed some better-than-average sand castles. That’s thanks to a new startup offering a unique service that’s becoming one of the most sought-after attractions in San Diego. San Diego Sand Castles is the one and only local company that teaches customers how to make eye-catching sand castles on the beach. The company is less than two years old, but it’s already reached the number one spot on...