The Long Tower Church, like St Augustine’s and Áras Cholmcille, almost certainly stands within the enclosure of the monastic settlement of medieval Derry. It gets its name from a round tower which stood here up to the 17th century. The round tower stood beside the Teampall Mór, Great Church, which was one of the wonders of its day, when it was built in 1163.

A Life of Colmcille was written in Irish in Derry between 1150-1182. It gives an account of the saint’s life and his alleged journey around Ireland as he founded churches and monasteries. This and other accounts claim that Colmcille established religious foundations in places such as Moone in County Kildare, Swords in County Dublin and Kells in County Meath. In this period Derry became head of all the Columban churches in Ireland.

While the Norman Invasion curbed the influence of the abbey, it continued to exist until the 16th century, and the Teampall Mór became the medieval cathedral. The building was devastated by an explosion in 1567, when English troops were using it as a gunpowder store.

St Columba’s Church, Long Tower, was built in 1784, and was paid for by both Catholics and Protestants. In the 19th century, the story of Colmcille continued to influence and shape the city and its public buildings. In late 19th and early 20th centuries Fr Willie Doherty enlarged and altered the church, making a modern Teampall Mór. Stained glass, mosaics, and inscriptions on the floor of the church and over the main door all link the church with Colmcille and the founding of the abbey of Derry.

Outside the church is a bullaun stone set in a wall below a calvary scene. Bullaun stones have one or more curved indentations which hold holy water.

The stone was installed here on 9 June 1898 – the saint’s feast day. It had been moved from its original location by St Columba’s Well by Father William Doherty the previous year.