The calculated distance (air line) between Sv. Ana v Slov. Goricah and Sežana is approximately 114 miles respectively 184 kilometers.
By car or train, the actual journey to Sežana is certainly longer, as only the direct route (as the crow flies) between Sv. Ana v Slov. Goricah and Sežana has been calculated here.
Air line (approximately)
184 kilometers
99 nautical miles