Gregans Castle, Manor house and tower complex in Burren region, Ireland

Gregans Castle is a property with a 15th-century tower and an 18th-century Georgian manor set on limestone terraces in County Clare's Burren region. The structures stand near Ballyvaughan village and today operate as a hotel with a restaurant.

The tower was built by the O'Lochlainn family, known as Princes of Burren, who lived there until 1654. After that point, the Cromwellian Settlement transferred ownership to the Martyn family.

The name Gregans derives from the Irish Caisleán na nGrágán, meaning "castle of the small hamlets," and the district was called the Barony of Gragans until the late 16th century, probably from a word for mountain bog still present on the western hills. The tower house was the seat of the O'Lochlainn chiefs, styled Prince of Burren. Frank Martyn, the last of the family, obtained a bar licence in the 1940s and tried his hand at inn-keeping.

The tower house stands across the road from the Georgian house that operates as the hotel, so the two are seen separately. The house's oldest surviving feature, the former kitchen fireplace with a crest keystone, is in what is now the Martyn Suite. The Burren's limestone terraces and hillside bog lie in the Ballyvaughan valley around both buildings.

The oldest surviving feature of the Georgian house is the former kitchen fireplace with a carved crest keystone, now standing in the room called the Martyn Suite. The tower house across the road, restored from ruin, is a private home and not open to guests.