The easiest way to get to Nanki Shirahama is by air or by train to avoid the traffic jams on the country roads leading into Tanabe City and Shirahama. An express way connecting the city to Osaka almost reaches Shirahama. The expressway is only two lanes, so it can get crowded in summer.
Buses frequently travel between many of the popular locations. One, Two, or Three Day Passes are available at the Shirahama JR Station for the Meiko Bus.
In the summer time it is very crowded so reservations are advised. There are also reservation centers that might be able to help.