The calculated distance (air line) between Seongnam-si and Uijeongbu-si is approximately 22 miles respectively 35 kilometers.
By car or train, the actual journey to Uijeongbu-si is certainly longer, as only the direct route (as the crow flies) between Seongnam-si and Uijeongbu-si has been calculated here.
Air line (approximately)
35 kilometers
19 nautical miles