Explore some of Kent’s hidden gems with the Heritage Open Days event. Many of the county’s historic buildings and attractions will open their doors for free during the annual four day celebration. What’s On previews some of the latest additions to the line-up.

From lavish mansions to prison quarters, all aspects of Kent’s history will be on show in this year’s Heritage Open Days event.

Part of a national scheme started in 1994, aimed at celebrating England’s extraordinary architecture and culture, Heritage Open Days offers free access to properties that are usually closed to the public or normally charge for admission.

Every year, for four days in September, buildings of every age, style and function throw open their doors, and volunteers organise a range of related tours, events and activities.

Last year, more than 1,400 organisations and some 40,000 volunteers organised thousands of site openings and events, jointly attracting more than a million visitors.

This year, Kent has several new attractions open to the public, including Hadlow Tower, near Tonbridge, a Grade I listed monument which was recently restored. The tower, which stands 175ft tall, once formed part of a grand house built in the late 18th century by Walter May, which was demolished in 1951 for building materials.

Visitors can climb more than 100 steps to the top of the tower, offering spectacular views over the area. Tours will be available from 11am to 3pm, from Thursday, September 12 to Sunday, September 15.

Visitors can also take a final look around Canterbury Prison, which closed in March and will soon be sold for redevelopment. Originally built in 1806, it was used as an archive store during the First World War, and formally closed in 1922.

It was then used as a repository for the Public Records office.

After use as a naval detention centre during the Second World War it reopened as a prison in 1947, and in its last few years accommodated foreign nationals.

Tours will include visits to the Victorian prison wings, gymnasium, kitchens and family visits hall. It is open from 9am to 5pm on Saturday, September 14 and Sunday, September 15.

The extraordinary Port Lympne Mansion and Gardens at Lympne, near Hythe, will be opened to the public for the first time.

Built around 1913 for former Hythe MP Philip Sassoon, the lavish property was inspired by a Roman villa, with marble columns and a sweeping stone staircase, and has many unusual murals decorating its interior, depicting wildlife from across the globe.

It is now a Grade II listed property belonging to the Aspinall Foundation, which uses the property to raise funds for the Port Lympne Wild Animal Park.

It will be open from 10am to 4pm on Sunday, September 15.

Visitors can also enjoy a tour of Boxley Abbey Barn in Sandling, near Maidstone.

The large medieval barn was the
hospiteum – a place where pilgrims and other lesser guests could find hospitality – for Boxley Abbey, founded in 1146.

At nearly 200 feet long it is among the longest surviving monastic buildings in the country, and is Grade I listed.

Recently restored, it has never been open to the public before. It will be open from 10am to 4pm on Saturday, September 14 and Sunday, September 15.

This year’s event also offers one of the last chances to view Eastgate House in Rochester High Street, prior to closure for conservation works.

Built in the late 1590s, the Elizabethan town house is set in its own gardens and is home to the Swiss chalet where Charles Dickens used to write his novels. It is open from 10am to 4pm, Thursday, September 12 to Sunday, September 15.

Heritage Open Days run from Thursday, September 12, to Sunday, September 15. Visit www.heritageopen days.org.uk