The nearest airport to Bahla is the Muscat International Airport which is 187 kms in distance. There are frequent buses from Muscat (Ruwi) for Ibri and Buriami that pass Nizwa and Bahla. It is best to hire a taxi or arrive on your own wheels. There are taxi services from Nizwa as well.
Since Bahla is a small fortified settlement, one can walk around the whole oasis to get from one end to the other. A single road cuts into the settlement leading to the fort entrance.