Ireland's second-largest medieval cathedral (after St Patrick's in Dublin) has a long and fascinating history. The first monastery was built here in the 6th century by St Canice, Kilkenny's patron saint. The present structure dates from the 13th to 16th centuries, with extensive 19th-century reconstruction, its interior housing ancient grave slabs and the tombs of Kilkenny Castle's Butler dynasty. Outside stands a 30m-high round tower, one of only two in Ireland that you can climb. Records show that a wooden church on the site was burned down in 1087. The existing structure was raised between 1202 and 1285, but then endured a series of catastrophes and resurrections. The first disaster, the collapse of the church tower in 1332, was associated with Dame Alice Kyteler's conviction for witchcraft. Her maid Petronella was also convicted, and her nephew, William Outlawe, was implicated. The unfortunate maid was burned at the stake, but Dame Alice escaped to London and William saved himself by offering to reroof part of St Canice's Cathedral with lead tiles. His new roof proved too heavy, however, and brought the church tower down with it. In 1650 Cromwell's forces defaced and damaged the church, using it to stable their horses. Repairs began in 1661; the beautiful roof in the nave was completed in 1863. Inside, highly polished ancient grave slabs are set on the walls and the floor. On the northern wall, a slab inscribed in Norman French commemorates Jose de Keteller, who died in 1280; despite the difference in spelling he was probably the father of Alice Kyteler. The stone chair of St Kieran embedded in the wall dates from the 13th century. The fine 1596 monument to Honorina Grace at the western end of the southern aisle is made of beautiful local black limestone. In the southern transept is the handsome black tomb of Piers Butler, who died in 1539, and his wife, Margaret Fitzgerald. Tombs and monuments (listed on a board in the southern aisle) to other notable Butlers crowd this corner of the church. Also worth a look is a model of Kilkenny as it was in 1642. Apart from missing its crown, the 9th-century round tower is in excellent condition. Inside is a tight squeeze and you'll need both hands to climb the 100 steps up steep ladders (under 12s not admitted). Walking to the cathedral from Parliament St leads you over Irishtown Bridge and up St Canice's Steps, which date from 1614; the wall at the top contains fragments of medieval carvings. The leaning tombstones scattered about the grounds prompt you to look, at the very least, for a black cat.