Newbridge House is unique in the Republic, not least because of the special arrangements made for its preservation. A 1985 agreement between the Cobbe family, which until then owned the house and demesne, and the then Dublin County Council, ensured the estate in Donabate, Co Dublin, has been preserved and opened to the public.

Given the success of this settlement, it is a pity that similar schemes have not been put into place elsewhere in the State so that other houses (and their contents) could be saved for the nation. A handsome Palladian villa designed by George Semple, Newbridge was built in 1737 for Charles Cobbe, later Archbishop of Dublin, who purchased large amounts of land in the area. The ashlar-faced front of six bays has a tripartite pedimented doorcase at the top of a broad flight of steps. The main rooms of the house have good proportions and some elegant plaster work but the tour de force is the large drawing room at the rear.

Although it is not clear whether this room, which serves as a picture gallery, was always part of the house or added at a later date, the present decorations date from around 1760. Visitors to the house who admire the drawing room's plaster work, attributed to Dublin stuccadore Richard Williams, should also try to visit Donabate's Church of Ireland church, where the Cobbe family pew has a ceiling also by Williams and dating from the same period. Details of the cost of the plasterwork in Newbridge's red drawing room - Williams was given six payments totalling £39 and 15 shillings for his work - are entered into account books preserved by the Cobbe family. These books are another reason for Newbridge's special character. Except for two missing volumes from the later part of the 18th century, there still exist full account books for the house and estate from 1720 to 1900.

In addition, an inventory for all items in the main house in 1821, diaries written by different members of the family over more than two centuries, plus journals and other material have been preserved. As a result, Newbridge is possibly the best-documented historic home in Ireland. Alec Cobbe, who grew up in the house and still stays there on a number of occasions, is working his way through this archive material with the eventual intention of producing a book covering the history of Newbridge. This will cover what has been lost, as well as the very many pieces of furniture still remaining in the house.

Among the pictures in the red drawing room, the two greatest losses occurred in the last century when a great grandson of Charles Cobbe, also Charles, sold works by Poussin and Hobbema to pay for the building of 80 cottages for his tenants in the Dublin mountains. Many of the other 17th and 18th century paintings in this room were bought on behalf of the Cobbe family by a vicar of Donabate, the Rev Matthew Pilkington, who wrote the first dictionary of painters in English.

The works on view include a landscape by Thomas Roberts. The drawing room's red flock wallpaper, applied in squares rather than long rectangular strips, is dated by Alec Cobbe to about 1790. The last major refurbishment in this room occurred during the 1820s when the heavy red damask curtains still in situ were bought from the firm of Mack Williams & Gibton at a cost of £70.

The same company also supplied the carpet and probably the pair of mahogany sofas covered in yellow silk damask, as well as a rosewood and marble chess table. Two mahogany serpentine sideboards in this room were supplied by Hicks of Dublin, while the carved gilt rococo mirrors dating from the 1770s carry the trade label of James Robinson of Capel Street. The eagle console tables are also Irish, as is the concert harp supplied to the house by Egans of Dublin in 1845.

Mack Williams & Gibton supplied other furniture in the house, such as the pair of mahogany sabre-legged chairs in the entrance hall. Dating from around 1816, these carry the Cobbe family crest - a pelican and a crown - as does the Portland Stone fireplace in this room.

The early 18th century mahogany side table is typically Irish, with a carved apron satyr-head mask and large claw feet. Originally in Adare Manor, its Italian black marble top is believed to be a later addition. On the table sits Archbishop Cobbe's personal journal and above hangs his portrait.

The plasterwork, contemporaneous with the building of the house, is simpler than in the red drawingroom or the adjacent dining room, where Richard Williams also seems to have worked. The fireplace in this room is of black Kilkenny marble and framed by a pair of Chinese Chippendale side tables made by Hearns of Fishamble Street in Dublin. The collection of 17th, 18th and 19th century blue and white porcelain was begun by a brother of Archbishop Cobbe who worked as as customs agent in China.

Also on display here are pieces from a 19th century Royal Worcester dinner service. The dining table came from Abbeville, Kinsealy, and is known to have cost £9, six shillings and three pence in 1830, while the chairs around it and the sideboard with open fretwork were made by Hicks of Dublin. Other Irish furniture includes a fine gilt pier glass between the two windows, which was made by Cranfield of Dublin, and an 18th century mahogany linen chest.

Originally a drawing room, the library assumed its present function after the redecoration of the house in the 1760s when a bow window was added here. The very large portrait in the library is of Archbishop Dillon of Toulouse and Narbonne, whose family had fled to France in the 17th century; Alec Cobbe's wife is a Dillon. Next door is a small museum, or cabinet of curiosities, once a common feature of such houses but now thought to be the only surviving example in Ireland and Britain.

While the origins of the museum go back to the mid-18th century, the display cases were made circa 1790, when the room was hung with chinoiserie wallpaper. This was sold in 1960, but from remaining fragments discovered, Alec Cobbe has redecorated the walls in the same style.

The collection of curiosities, augmented through the 18th and 19th centuries, is currently in storage awaiting restoration, but the cases have been filled with a variety of similar items which give an excellent sense of how domestic museums from the period would have looked.

There are many other fine pieces throughout the house, not least an impressive collection of family portraits. Downstairs, a couple of the servants' rooms, including the kitchen, have been restored, while in the courtyard a number of coaches - most importantly that built for the Lord Chancellor in 1790 - are on show. The demesne, which includes a traditional farm, is also open to the public.