The calculated distance (air line) between Castanheira do Ribatejo and Coimbra is approximately 89 miles respectively 143 kilometers.
By car or train, the actual journey to Coimbra is certainly longer, as only the direct route (as the crow flies) between Castanheira do Ribatejo and Coimbra has been calculated here.
Air line (approximately)
143 kilometers
77 nautical miles