The following text is from the original listed building designation:
RAMSGATE SION HILL TR 3864 NW (south side) 13/373 Group of 4 cannon and tideball post GV II Group of 4 cannon and tide ball post. Cannon dated 27th November 1821 and engraved with Royal Harbour of Ramsgate and town Arms, with serial numbers 2.3.13, 2.3.10, 2.3.17, 2.3.15. Muzzle loaded on restored trucks set in C20 concrete seating area, with the stump of the late C18 tide-ball mast in the centre (See Busson, illus, 29+33).
Listing NGR: TR3817664648

English Heritage, List of Buildings of Special Architectural or Historic Interest (Map). SKE16160.