This castle does not feature on many maps or reference sources. It can be accessed via permission of Polnoon Farm, G76 OPE which is mile or so south of Eaglesham and is situated about 100 yds/metres from the road across a field which is obviously used to house cattle, i.e. terrain is fairly rough.
In essence what remains is a conical mound, possibly natural, on and around which are tumbled blocks of masonry with one such block having found its way into the river below (see image).
Location makes sense in that the castle was built on a high natural elevation surrounded on one side by the local river, the Polnoon Water (a sort of natural moat-and water source) and close to a water mill which in its day would have been an important economic resource.
Research suggests that the castle was built in the late 14th century, possibly on the site of an earlier castle, by Sir John Montgomery financed by a ransom paid by Sir Henry ‘Hotspur’ Percy who was captured at the Battle of Otterburn in 1388. The castle was refurbished in 1617 but in ruins by 1676 and abandoned by end of that century. Apparently no formal excavation of the site has been undertaken.
The chaotic nature of the site may be attributed to locals using the castle as a quarry site for local buildings. In support of this ‘looting’ theory, the image at the top of this posting represents an armorial stone found above the entrance to the (now defunct/vacant) Cross Keys pub in Montgomery Street, Eaglesham which may well have originated form the castle. The triple Fleur-de-lis is the family crest of the Montgomerys whilst the triple ring is the family crest of the Eglintons. This stone may have recorded the marriage of a Montgomery with a Eglinton Heiress in the 14th century, possibly Sir John Montgomery and Elizabeth of Eglinton.
The name Polnoon may have been derived from either:
- An old Scots word ‘poinding’ meaning ransom, or
- ‘Pol’, a deep bend or pool in a river which is indeed a feature of the castle’s location.
Overall, a satisfying morning spent finding and researching the history of this little known site.