The calculated distance (air line) between Walton-on-the-Naze and Islington is approximately 63 miles respectively 101 kilometers.
By car or train, the actual journey to Islington is certainly longer, as only the direct route (as the crow flies) between Walton-on-the-Naze and Islington has been calculated here.
Air line (approximately)
101 kilometers
54 nautical miles