Rising above the River Nore, Kilkenny Castle is one of Ireland's most visited heritage sites. Stronghold of the powerful Butler family, it has a history dating back to the 12th century, though much of its present look dates from Victorian times.

During the winter months (November to January) there are 40-minute guided tours, which shift to self-guided February to October. Highlights include the Long Gallery with its painted roof and carved marble fireplace. There's an excellent tea room in the former castle kitchens, all white marble and gleaming copper.

The first structure on this strategic site was a wooden tower built in 1172 by Richard Fitz Gilbert de Clare, the Anglo-Norman conqueror of Ireland better known as Strongbow. In 1192 Strongbow's son-in-law, William Marshal, erected a stone castle with four towers, three of which survive. The castle was bought by the powerful Butler family (later earls and dukes of Ormonde) in 1391, and their descendants continued to live here until 1935. Maintaining the castle became such a financial strain that most of the furnishings were sold at auction. The property was handed over to the city in 1967 for the princely sum of £50.

For most visitors, the focal point of a visit is the Long Gallery, which showcases portraits of Butler family members, the oldest dating from the 17th century. It is an impressive hall with a 19th-century timber roof vividly painted with Celtic, medieval and Pre-Raphaelite motifs by John Hungerford Pollen (1820–1902), who also created the magnificent Carrara marble fireplace, delicately carved with scenes from Butler family history.

The castle basement is home to the Butler Gallery, featuring contemporary artwork in temporary exhibitions, and to a popular summertime tea room housed in the castle kitchen. You can access the Butler Gallery and cafe without paying admission.

About 20 hectares of public parkland extend to the southeast of Kilkenny Castle, framing a fine view of Mt Leinster, while a Celtic cross-shaped rose garden lies northwest of the castle. A gate on the north side of the park leads steeply down to the riverside, where you can walk back into town at St John's Bridge.