The problem is that many are too small to cope with the huge numbers that descend upon them. Many have reached saturation point.
"Places like Bleinhem Palace can cope with more than 200,000 visitors each year, but at smaller sites like Haworth such numbers put great strain on the fabric of the buildings," said Dr Robert Barnard, chairman of the Bronte Society, which owns Haworth Parsonage, the sisters' home.
One result is that the ceiling in the Parsonage library has started to sag, because of the hordes viewing the exhibition of the lives of the Brontes in the room above. "People are pausing in the room to read the display panels and this is putting tremendous weight on the joists," Dr Barnard said.
Although the information panels have now been placed by the walls of the room, where the support is stronger, the floor continues to sag. The society is to insert a strengthening pin and hopes this can be done without the house having to close.
The sagging happened despite a successful attempt seven years ago to cut numbers of visitors to the 220-year-old Parsonage by half, to about 100,000 a year, by raising admission prices.
"There's a delicate balance to be found," said Dr Barnard. "We try to ensure that only small groups of people walk through together. We're not just concerned about the fabric of the building. It's also a question of atmosphere. Haworth is a fairly bleak and lonely place but you don't catch too much of that mood if you are walking around with 40 other visitors."
It is a concern shared by the Wordsworth Trust, which owns Dove Cottage, the poet's 17th-century home in Grasmere. It receives around 80,000 visitors a year, all of whom must view the cottage on a guided tour.
"We are close to our maximum intake of visitors," said the Trust's Mark Bains. "A guided-tour system enables us to limit the number of visitors to 15 in any room. Our guides tell people about the history of the cottage and that means we don't have to clutter the place with panels and information."
But the cottage remains vulnerable. Earlier this year the Trust spent pounds 1,500 on restoring the wooden staircase and floorboards in the bedroom. "Without those repairs we would not have been able to open to the public," said Mr Bains.
The garden at the rear of the cottage is also restricted, with access to the public only allowed in good weather. Dove Cottage's chief guide, George Kirkby, who restored the garden, recently said: "A small garden and a lot of feet just don't go together." Across the Lakes, near Sawrey, Beatrix Potter's home has already received 44,000 visitors this year. "It is a small house and has been very busy," said Caroline Oudermars of the National Trust. "We had to introduce a system where all coaches had to book in advance. If they turn up unannounced it causes great problems. In small places like Hill Top a lot of damage can be caused by people simply brushing against walls and curtains."
Other National Trust houses have required more drastic measures. The Trust has introduced timed tickets at Winston Churchill's home at Chartwell and the garden at Sissinghurst Castle, home of Harold Nicolson and Vita Sackville-West.
It is not just homes that suffer from visiting throngs. The National Trust spends pounds 500,000 a year maintaining footpaths. The grass on Mam Tor, in the Peak District, suffered great erosion because walkers habitually strayed from poor footpaths. Today, the grass has made a full recovery as walkers keep to paths made from recycled stone slabs.Reuse content