The calculated distance (air line) between Tham Phannara and Nakhon Si Thammarat is approximately 39 miles respectively 63 kilometers.
By car or train, the actual journey to Nakhon Si Thammarat is certainly longer, as only the direct route (as the crow flies) between Tham Phannara and Nakhon Si Thammarat has been calculated here.
Air line (approximately)
63 kilometers
34 nautical miles