Aske Hall: The Yorkshire stately home that's only open once a year

The Georgian country house near Richmond has been the home of the Dundas family, Marquesses of Zetland, since 1763.

Every September they open up their Grade I-listed mansion to the public for a limited number of guided tours as part of the Heritage Open Days festival. This year, visitors can book to see inside the house on September 18 and 19, with tours at 10am, 11am and 12pm. Group sizes are restricted to 15 people.

This is what it's like to run one of the most traditional pubs in the Yorkshire DalesAske Hall was mentioned in the Domesday Book, but it wasn't until the 16th century that a significant manor house was built on the site by the Bowes family. In 1727, new owner Sir Conyers Darcy commissioned the architect who had designed Duncombe Park in Helmsley to transform Aske.

When Sir Lawrence, the first of the Dundas baronets, took ownership of the estate in 1763, he hired prominent architect John Carr, realising that Aske could become one of the greatest houses in the north. He wanted to establish a powerful dynasty whose seat was at Aske, enabling them to influence political affairs in nearby Richmond. The project saw the building of new offices, a bakehouse, wash-house, scullery, kitchen, strongrooms, family rooms and a staircase.

When Thomas Dundas, by now the second Earl of Zetland, was living in the hall, he funded further renovations, hiring Ignatius Bonomi, the architect who had worked on Durham Cathedral and St Nicholas House in Richmond. A Jacobean frontage was added, and two balconies. The tower on the west front was remodelled.

In the 1960s, the third Marquess of Zetland decided to reduce the size of the house and remove the ballroom.

Aske remains an impressive pile today - it is home to a collection of 18th-century furniture, paintings and porcelain which visitors can view as part of the tours. The grounds are thought to have been landscaped by Capability Brown, and include terraced lawns, a walled garden, a gothic folly and a lake with Roman-style temple. A coach house and the remains of a 12th-century peel tower built as a defence against Scottish raiders can also be seen.

Castle Howard decorated for Ellie Goulding's weddingThe Dundas family have embarked on a major modernisation programme since the turn of the millennium which has seen them reduce the Zetland estate's dependency on agriculture and commercial shoots for its income. They've sold a sawmill and let out the home farm to tenants.

The Victorian stable block, indoor riding school and clubhouse have all been converted into modern offices - the stables had been redundant since the 1920s and were used only for farm storage. The blacksmith's workshop has become a meeting room.

The current Marquess's eldest son, Robin, ended the family's reliance on long-serving land agents and took on the role himself. He has also overhauled the residential lettings business, modernising the estate cottages and reforming the traditional tenancy agreements.

Previously, the properties had been let to long-term sitting tenants, many of whom had vague ancestral connections to the Dundas family, some of which dated back to the 19th century, and were paying peppercorn rents. Some of the houses were in a poor state of repair and there was little incentive to finance improvements when the turnover was so low. Robin introduced short-hold assured leases and diversified the range of occupants.

This World War Two gun battery was hidden on a Yorkshire farm for more than 70 years In 2009, the Zetland estate was rocked by the death of its gamekeeper's son Phillip Scott, who was killed in a bomb blast while serving in Afghanistan. The 30-year-old had worked on the estate before joining the army, and his funeral was held in the chapel at Aske Hall.

To book a place on an Aske Hall tour in September, email [email protected].