Old St Paul's Cathedral in length including the portico, and across the transepts, and Winchester Cathedral, the longest remaining medieval church, is long and across the transepts. The cathedral had one of Europe's tallest church spires, the height of which is traditionally given as , surpassing all but Lincoln Cathedral. The King's Surveyor, Christopher Wren (1632–1723), judged that an overestimate and gave . William Benham noted that the cathedral probably "resembled in general outline that of Salisbury, but it was a hundred feet longer, and the spire was sixty or eighty feet higher. The tower was open internally as far as the base of
Cathedral of the Immaculate Conception, Sligo needed replaced. He engaged George Goldie, one of the foremost Catholic architects in England in the nineteenth century, and the Cathedral was opened for divine worship on 26 July 1874 by Cardinal Paul Cullen of Dublin. The cathedral was built in a Norman style, and it is the only Norman styled cathedral in Ireland. It can seat 1400 people. It has an impressive spire at the front and large apse in the Sanctuary. Cathedral of the Immaculate Conception, Sligo "This article refers to the Roman Catholic cathedral. For the Church of Ireland cathedral, see St John the Baptist Cathedral, Sligo."