Castle Caereinion Signal Box is a Tyer & Co design and dates from 1907. It is located at Castle Caereinion station (nprn 415837) on the preserved Welshpool and Llanfair Light Railway (nprn 43037). A two storey structure of brick-to-floor construction under a pitched slated roof, it has an external access stairway at the west end. The 10-lever frame is original and although the box has been boarded-up and out of use for many years, it has survived in good condition, being used as a store for the railway. It is probably the only surviving example of a Tyer's signal box.

Sources include: Peter Kay, Signalling Atlas and Signal Box Directory (Third Edition), Signalling Record Society, Wallasey, 2010, p.67. For further information on the types and designs of signal boxes see: The Signalling Study Group, The Signal Box - A Pictorial History and Guide to Designs, OPC, 1986.

B.A.Malaws, RCAHMW, 25 November 2016.