Westport House in Westport, Ireland is the stately home of Lord Altamont the Marquess of Sligo. It was built by the Browne family in the 18th Century, on the site of an O'Malley castle whose dungeons are still present today. The architects were Richard Cassels who built (1730 ) the east section of the house facing the town, and later James Wyatt who built the other three facades to form a quadrangle. Later the quadrangle was filled in with a grand staircase. North and south wings were added to the designs of Benjamin Wyatt. The south wing, which contained a library, was burned soon after it was built due to a defect in the heating system. It was subsequently rebuilt.
A model farm was built in the demesne in the early part of the 19th century with accommodation housing animals and animal feed.
The remains of an old boathouse open to the sea.
Colonel John Browne (1638-1711) who built the original Westport House married Gráinne O'Malley’s great great granddaughter, Maude Burke. He was a Roman Catholic who fought on the Jacobite side in the War of the Two Kings. His descendants, however, converted to the established Church of Ireland, and prospered.
The current Marquess of Sligo is Jeremy Browne. He and his family still own and live in the country Park and have been responsible for its success as a commercial enterprise.
Westport House also has a Pirate Adventure Park with a Pirate Ship thrill ride, Pirates' Plunge flume ride, mini Railway, white swan pedal boats, cannon-ball run slippery slide, Pirate's Den indoor soft play area, dungeons, Pirate's Playground, pitch and putt, fishing, Grace's Bar and Cafe and a large Caravan and Camping Park set in secluded woodland.
Designed by the famous architects Richard Cassels and James Wyatt in the 18th century, Westport House is located west of the Shannon and is considered one of Ireland's most beautiful historic homes open to the public. Westport House is situated in a superb parkland setting with lake, terraces, garden magnificent views overlooking Clew Bay, the Atlantic Ocean, Achill, Clare Island and Irelands Holy Mountain, Croagh Patrick. It was built and is still privately owned by the Browne family, who are direct descendants of the 16th-century Pirate Queen Gráinne O'Malley.