Castleton currently has 40 mapped postboxes recorded by The Postbox Hunter. The postboxes in Castleton include 7 recorded royal cyphers. The most common is EIIR, recorded on 23 postboxes, representing 57.5% of the mapped total. Other recorded cyphers include GR, VR, EVIIR and GVIR. Among the recognised royal cyphers in the data, VR is the earliest recorded and EIIR is the most recent. The most commonly recorded postbox type is Pillar, with 14 mapped examples. The data contains 4 different recorded postbox types. Across the available tagging data, 4 designs are represented. This information is generated from the latest postbox location and tagging data available to The Postbox Hunter.