St Columba's was built in neo-Renaissance style in 1784, it was the first Catholic church erected in the city after the reformation. It is built on the site of a famous medieval churches the Tempull Mor or Great Church, built in the 1160's, all traces of the Tempull Mor disappeared in the seventeenth century.

This cathedral was built between the years of 1628 - 33 in the contemporary Jacobean Gothic style. This is an aisled rectangural church with battlemented exterior, and decorated windows. The wooden ceiling of the nave displays some exceptionall fine workmanship.

In the chapter house in the northwest of the church is a display of memorabilia of the siege of Derry and some spent cannonballs.