Some of the country's finest private houses open their doors to the public for a limited period each year. Rosita Bolandgets a look in.

'Michael O'Leary didn't do the organisation any favours," Jim Soden of Arabella House in Ballymacelligott, Co Kerry says wryly. For once, it's not the airline industry that's being discussed, it's Section 482 properties.

There are 169 privately-owned properties in the State of "significant horticultural, scientific, historical, architectural or aesthetic interest" which qualify for tax relief under Section 482 of the Taxes Consolidation Act 1997.

It can be claimed for expenditure on things such as repair, maintenance or restoration. In return, they must open for at least 60 days of the year, 40 of which must be between May 1st and September 30th, with 10 of those days at weekends.

There used to be 170 of these properties - Michael O'Leary's Gigginstown House in Mullingar, Co Westmeath was briefly on the list at one point.

While the norm is for the public to simply turn up at the advertised opening hours to visit these tax-relief properties, to access Gigginstown you had to make an appointment in advance and this did not prove popular. O'Leary withdrew his house from the scheme in 2004.

The current Section 482 properties range from houses and castles to public buildings used as businesses. For instance, in Dublin the Westin hotel on Westmoreland Street makes it onto the list, as does Berry Brothers & Rudd Ireland wine shop on Harry Street, Brown's Barn in Citywest and Doheny & Nesbitt's bar on Lower Baggot Street.

Then there are some well-known houses and gardens which have long been open to the public, such as Bantry House in Cork and Powerscourt in Co Wicklow. But the most interesting to the general public of the 169 properties are those privately owned historic houses that one would not usually have a chance to see, but which one can visit at certain publicly pre-advertised times of the year.

Arabella House is an 18th-century Georgian house over basement in an area of north Kerry so rural that it takes three phonecalls to the owner and three stops to ask directions locally to find it. You really have to be determined to get to it, but that's part of the charm and excitement in looking for these houses.

Arabella House lies at the end of a long potholed avenue: a lovely, unusual double bow-fronted house that stands like a secret stone gem among lush fields.

Jim and Muriel Soden, originally from Cavan, have lived here with their four daughters since 1998. When I arrive, everyone is out, apart from Jim, who shows me around: all Section 482 properties will have someone at home to give an informal tour.

"It was habitable from the beginning, but we were aware the house needed work," Jim says. Even nine years on, it's clear this was an understatement. For starters, the house needed a new roof. And while it is hugely atmospheric, half of the house is still a work in progress and unused.

The house was originally built by Arthur Blennerhasset in 1760 for his wife, Arabella. It stayed in the family for some generations, before being bought by the Peetes, who lived there continuously from 1840 until 1970.

"There used to be 450 acres with the house and it got divided up by the Land Commission in 1970, and given to people in the area. We have eight acres now, the remnants."

Long before the land was divided, the Peetes planted extensive orchards in 1890. "Pears, apples, rhubarb, raspberry canes - they supplied all of north Kerry." The Sodens still pick apples from these old orchards, and their wild gardens with tumbledown buildings are both haunting and picturesque in their overgrown state.

The features of particular architectural significance about this house are the portico, in Kilkenny limestone, the double return staircase and the cedarwood doors and floors of the main reception rooms. "Generally what we show people are the outside view, and explain about the various additions to the building over time, and then show them one of the rooms we are renovating and take them up the stairs," Jim explains. He points out where one of the Peetes carved his name into the wooden window-frame.

The house has been open for several years, and many of those who come to visit had family members who worked in the orchards for the Peetes. Although Jim says that "the family can't be at ease in the months the house is open", in fact they receive very few visitors. When I visited, the house was almost at the end of its regulatory 60 day-opening, and had had fewer than 15 visitors, most of whom had arrived in groups of twos and threes. "Our busiest year ever," he says without irony.

Henrietta Street is Dublin's oldest and most famous Georgian street. Number 12 is owned and lived in by Ian Lumley of An Taisce, who lets some of the rooms. The sticker on the door informs the visitor that the house is open from 9am to 1pm during May and June (when I visit) and implores you to "knock loudly". I obey with vigour, three times. Twenty minutes later, I'm still standing on the doorstep. The workman painting next door assures me he's seen someone go in earlier that morning and not come out again. Bang harder, he advises; it's a big house. I fairly wallop that iron knocker. Nothing happens.

Then one of the tenants arrives on his bike and lets me in. As it happens, there were three people inside the house all the time, but they simply couldn't hear the knocking, so enormous is this 18th-century house. And even though the house is coming to the end of its two-month opening period, I am the only visitor of the season so far.

Even if you haven't been here, you might have seen the interior of this house, as it is often used in period films. But unlike the visual trickery of film sets, this house looks and feels like the genuine period piece it is from the second you cross the threshold into its dim, high hallway with original, worn wooden staircase and peeling paint. Visitors get shown into the interconnecting first-floor rooms, a pair of really astonishing rooms with high ceilings, faded period furniture and huge fireplaces, that overlook a large walled garden.

The house is potent with its history, and unlike so many other Georgian buildings, hasn't been ruined by over-restoration. You feel as if you are in a portal to the past in this extraordinary house.

Down in Baltimore, Co Cork, Bernie and Patrick McCarthy's 13th-century tower house, Dún na Séad Castle, is now a Section 482 property. A decade ago, it was a ruin. "It's a registered national monument, but it's always been privately owned," explains Bernie.

There were eight years of extensive reconstruction work before they could move in - the first people to inhabit the castle since the 17th-century. The first thing you notice when you go up the stairs are the photographs of the roofless walls of the ruin. Dún na Séad is right in the middle of the village and gets lots of visitors all summer: tourists, historians, architects and archeologists. "You get some very daft questions from people," Bernie says. "I've had people ask me if this is the original roof, and if this furniture was in the castle all the time."

What the public sees is the great hall, a huge and impressive room with a double-height ceiling. The McCarthys have put in period furniture, stags' heads and a wooden candelabra from a convent. The wood is all green oak, which was still drying out when it was installed. "We still hear it cracking sometimes as it dries out," Patrick says.

You can also go upstairs for a terrific view from the narrow ramparts that overlook Baltimore village and nearby Sherkin Island across the bay.

It was from Dún na Séad Castle in 1537 that the then owner, Fineen O'Driscoll, went out to meet a Portuguese ship carrying a cargo of wine intended for others. O'Driscoll invited the captain and crew to dinner in the castle and then imprisoned them and stole all the wine. "Living here is like living in a cathedral of history," Bernie says. "The fact that it all happened between these walls. We tell visitors that it's the best thing about living here."

For locations and opening times, see

http://www.revenue.ie/pdf/sig_prop1.pdf or Fáilte Ireland's booklet, Properties of Significant Interest in Ireland. Some properties charge a small admission fee