National Trust stately home Nostell Priory to open for free for one weekend only

The 18th-century Palladian mansion near Wakefield is a National Trust property that normally charges for entry to the house and grounds.

But on September 20 and 21, admission will be free to mark the Heritage Open Days festival, which promotes the accessibility of historic sites.

Thundercliffe Grange: The Georgian mansion that became a lunatic asylumVisitors will be able to enjoy exhibitions about the history of Nostell - which was built for the Winn family in 1733 - and view the house's world-renowned collection of Thomas Chippendale furniture.

The grounds include 300 acres of parkland and gardens that are at their best in autumn - there are lakes, wildflower meadows, woodland, a kitchen garden, menagerie garden and adventure play area. The old stable block is now a visitor centre with a shop and courtyard cafe.

Aske Hall: The Yorkshire stately home that's only open once a yearThe attraction - which has been run by the National Trust since 1953 - has also released an exciting autumn events programme beginning this month.

Highlights include a tour of the historic stables (September 11, 2-3pm), a willow-making demonstration by artisan crafters (September 15), an Upstairs Downstairs tour of the mansion (September 19, 1.30-3pm) and the annual Apple Week celebrations from September 23-29.

This is what it's like to run one of the most traditional pubs in the Yorkshire DalesThere's also a talk about the Victorian naturalist and explorer Charles Waterton, who lived at nearby Walton Hall, by author Barbara Phipps on September 24 from 10.30am-12pm, while on September 27 Nostell launch the first of their Nostell Nights adults-only evenings, which will offers visitors the chance to step inside parts of the house that are not usually open to the public.