The calculated distance (air line) between Hollogne-aux-Pierres and Sint-Niklaas is approximately 68 miles respectively 110 kilometers.
By car or train, the actual journey to Sint-Niklaas is certainly longer, as only the direct route (as the crow flies) between Hollogne-aux-Pierres and Sint-Niklaas has been calculated here.
Air line (approximately)
110 kilometers
59 nautical miles