Some believe they served as bell-towers where hand-bells rung out a window called the faithful to prayer.
Kildare and Mayo each have five round towers, more than any other county in Ireland.
Both Killala’s and Tourlough’s towers are complete at 25.5m and 22.9m respectively.
The small village of Aghagower, a few miles from Westport is home to a round tower in a cemetery, which though incomplete, dominates the small village. Built between 973 and 1013 it stands 16 metres high with no roof. This tower, believed to have been founded by St. Senach--Bishop of Aghagower, appointed by St. Patrick--shows signs of having suffered fire damage and was reconstructed in part. Traditionally, the doorways are a couple of metres or higher above ground, so the addition of a second doorway in this tower is a an attempt at making it more accessible at ground level. Aghagower is on the Tochar Paidrig (the Pilgrim's Walk) which begins at Ballintubber Abbey and traverses to Croagh Patrick, the holy mountain. At Aghagower, traditionally pilgrims stop to perform the ‘rounds,’ a series of prayers before progressing to The Reek.
Balla’s round tower is incomplete and stands at 10 metres, somewhat shorter than typical and is the last vestige of a monastery founded by St. Mochua in the 600s. Though destroyed by fire in 1179 the Ordnance Survey memoirs of 1838 is the next time this tower is referred to. There are two doorways in this tower. The upper, possibly original door is about 7 metres above ground level, higher than usual while the lower doorway The lower, four-stone arched doorway appears to have been added in the late medieval period. Located about 12km southeast of Castlebar, the round tower is just off the main road through town and easily accessed.
Killala’s round tower stands tall at over 25 metres in the centre of the town where St. Patrick founded a church around 442 or 443 and appointed St. Muredach as bishop. St. Patrick is said to have baptised 12,000 new converts to Christianity in a single day at a holy well near the town. The tower is intact, though it sustained damage to its body and roof from lightning in the 18th century and it is known that the Office of Public Works performed some repairs in 1841. The tower is constructed of limestone with some sandstone used over the entry.
Meelick’s incomplete tower, 6km southwest of Swinford, stands at 21 metres and was built between 923 and 1013 A.D. on a site associated with St. Broccaidh. Constructed of sandstone, the lichen growing on it makes it slightly gleams in the sun. Little is known of its history, but a vaulted floor above the doorway is suggestive of additional security for self-defense purposes.
Turlough, located 8km northeast of Castlebar boasts a 9th century intact round tower, which at almost 23 metres is slightly shorter-than-average. Situated on an elevated site, it would have offered good vantage point to detect oncoming enemy invaders. It’s cap was repaired in 1880 by the OPW and unlike the traditional pointed capstone typical of round towers, appears to sit somewhat squatly on top.