Altamont House, 18th century manor house in Tullow, Ireland

Altamont House is a manor near Tullow, County Carlow, Ireland, set beside the River Slaney and surrounded by gardens, a lake, and woodland. The grounds include an ice age glen, a bog garden, and an arboretum connected by paths that run through old oak trees.

The house's early origins are unclear, with some claims it began as a convent possibly dating to the 16th century. Its central section dates from the 18th century, and the east-facing sections were built by the St George family, largely to turn the house toward a newly built road. In the 1840s the Dawson Borrer family refurbished house and gardens, adding a lake dug as famine relief. Feilding Lecky Watson bought Altamont in 1923 and expanded the gardens; his daughter Corona North continued after his death in 1943.

Altamont House and its gardens are well known among garden lovers across Ireland, who travel from far away to see the rare plant collections. The estate is especially visited in spring, when rhododendrons and azaleas are in bloom and color the grounds.

The estate is best explored on foot, as paths lead through woodland, bog, and open areas across the grounds. Sturdy shoes are a good idea, since the terrain can be muddy at certain times of year.

A Wellingtonia tree, also known as Giant Redwood, was planted in the gardens as a memorial to the Battle of Waterloo. This species comes from North America and is rarely found growing in Irish gardens.