Grade I-listed Apethorpe Hall in Northamptonshire has been opened to visitors following a major £4m redevelopment of the property.

Funded by English Heritage, the work on the property included the restoration of the interior areas - including the plasterwork, oak panelling and ornate fireplaces - by traditional craftspeople.

A large section of the timber-framed roof has been repaired and re-roofed using thousands of local stone slates. In total around 150,000 man-hours of skilled labour has been used over the past two years on repair and conservation work.

Apethorpe Hall was initially built in the 15th century and underwent a significant rebuild between 1622 and 1624 to receive James I.

It is still considered to having one of the finest sets of Jacobean interiors of the period, with decorative plaster ceilings, fireplaces and panelling.

The house was abandoned in 1982 and, following many years of neglect and decay, fell into a state of significant disrepair and was in danger of being lost forever.

In 2004, as the protector of England's legacy of historic buildings, English Heritage stepped in and saved it.

Following compulsory purchase action, English Heritage took over the site in and undertook a multi-million pound programme of rescue works, with the aim of ultimately selling the Hall for use as a private country house.

Until a sale is agreed, the property will be open to visitors as an heritage attraction.

Steve Bax, visitor operations director for the East of England, said: "Apethorpe Hall is a truly fascinating building, and the team at English Heritage have made some significant discoveries about the place since we've been responsible for it.

"Visitors to the Hall will be able to see the secret passageway we uncovered as a result of our restoration work, which links King James's state apartment to the room that was used by his favourite courtier, the Duke of Buckingham, George Villiers."