Really the best beaches you find on the east side of Marbella in Los Monteros, Elviria and El Rosario area, Long sandy beaches with most of them friendly for children as well. Marbella town offers you some great beaches as well. Puerto Banús has on both sides of the port good beaches. Most of the beaches in the Marbella area has blue flag! Towards Estepona you will find some nice places too. Estepona town has great beach in the center of town and after the port you find Playa de Christo a favorite for many.