The Tower House appears on this site regularly, often under the guise, or at least the name, of a castle. However, tower houses are distinct from, and appeared later than, castles which were introduced into Ireland by the Anglo-Normans in the 12th and 13th century and are substantial defensive structures, fortified keeps on raised ground within a walled enclosure. According to archaeologist Colm Donnelly, tower houses should be regarded as a species within the castle genus. While they were often erected inside a protective bawn wall, the typical tower house was a less complex building than the Norman castle, being, as its name implies, a tall, single tower. In this respect, the structures bear similarity to what are known as Peel Towers in northern England and the Scottish borders, and which date from much the same period. 

The origins of the Irish tower house date back to 1429. In that year, a statute issued by Henry VI, King of England (and ostensibly Lord of Ireland) declared, ‘It is agreed and asserted that every liege man of our Lord, the King of the said Counties, who chooses to build a Castle or Tower House sufficiently embattled or fortified, wither the next ten years to wit 20 feet in length, 16 feet in width and 40 feet in height or more, that the commons of the said Counties shall pay to the said person, to build the said Castle or Tower ten pounds by way of subsidy.’ The ‘said Counties’ to which this document refers covered the area taking in parts of what are now Meath, Louth and Kildare in which English authority still held sway and which was known as the Pale. And the intent behind the statute was to ensure better protection of that area from incursion by those who lived outside its perimeter.  It is often proposed that this piece of legislation, with its financial incentive, did much to encourage the popularity of tower houses within the boundaries of the Pale. However, soon enough they also began to appear elsewhere throughout the country, their construction popular among both descendants of the Anglo-Norman families and members of the Gaelic nobility. They continued to be built for some 200 years and it was only in the first half of the 17th century that they were superseded by fortified houses. It has been estimated that between 1400 and 1650 in the region of 3,000 tower houses were constructed. Many of them survive to the present day, in various states of repair.

No two tower houses are identical but customarily they were square or rectangular in shape, running to four or five storeys in height and with a single arched doorcase on the ground floor providing the only point of access. A number survive in County Tipperary which, unusually, are circular; one of these at Moorstown was shown here three years ago (see In the Round « The Irish Aesthete). Here is another, Ballynahow which is exceptionally well-preserved. It is believed to date from the early 16th century when erected by a branch of the Purcells, a family closely allied to the powerful Butlers, and whose main base was at Loughmoe (see A Former Family Seat « The Irish Aesthete): the latter incorporates a more typical tower house into a later fortified house. Ballynahow, on the other hand, is free-standing and, as already mentioned, cylindrical in shape. Thereafter much of its design and layout follows the typical pattern, with a large vaulted ground floor reached by an arched door on the east side (with a murder hole strategically placed above) and only narrow slits in the walls at this low level to provide light to the interior while not leaving those inside exposed or visible to attack. Larger window openings can be found on the upper floors, along with substantial chimneypieces as these were the main residential quarters for the occupants. They were reached thanks to a stone spiral staircase climbing around the immediate inside of the building. Four machiolations are evenly spaced along the roofline; the tower house would originally have been finished with a conical dome. It appears that as late as the 1840s the lower floors of Ballynahow were still in residential use and this may help to explain why it is in such good condition.