This fine Palladian mansion was the birthplace and Irish headquarters of Charles Stewart Parnell (1846–91), the 'uncrowned king of Ireland' and one of the key figures in the Irish independence movement. Avondale House was designed by James Wyatt in 1779. Its highlights include a stunning vermilion-hued library and the American Room, dedicated to Parnell's eponymous grandfather, admiral of the USS Constitution during the War of 1812. The house is closed for renovations until 2020 but the gardens remain open dawn to dusk year-round.

From 1880 to 1890 Avondale was synonymous with the fight for Home Rule, which was brilliantly led by Parnell until 1890, when a member of his own Irish Parliamentary Party, Captain William O'Shea, sued his wife Kitty for divorce and named Parnell as co-respondent. Parnell's affair with Kitty O'Shea scandalised this 'priest-ridden' nation, and the ultraconservative clergy declared that Parnell was unfit to lead – despite the fact that as soon as the divorce was granted the two lovers were quickly married. Parnell resigned as leader of the party and withdrew in despair to Avondale, where he died the following year.

The magnificent 209-hectare estate that surrounds the house is managed by the Irish Forestry Service, Coillte (, and there are a number of hiking trails, such as the Railway Walk; download a trail map from the website.