Airport: You can take the Bus to Sassari.
Bus: From Sassari, take the Bus for Castelsardo or Santa Teresa di Gallura and get off at the Marritza stop.
Train: Take the train from Sassari, direction Sorso. From Sorso's train station, catch the bus for Castelsardo o Santa Teresa di Gallura and get off at the Marritza stop.
It is highly recommended to have your own kind of transportation to reach the B&B!