Take a look inside Kent’s unsung wonders as part of this year’s Heritage Open Days. Chris Price picks out his favourites.

This weekend is your chance to explore some of the county’s most fascinating buildings for free.

Celebrating England’s architecture and culture, Heritage Open Days take place over four days each September – offering access to properties that are usually closed to the public or normally charge an admission fee.

All the buildings taking part are open free of charge, with friendly, knowledgeable guides on hand to answer questions.

In 2010 about one million people took part and this year the likes of Fort Amherst in Chatham, Smallhythe Place in Tenterden and Whitstable Castle will open their doors.

Some of the best places to visit are the smaller or lesser known attractions, such as Herne Windmill, near Herne Bay or St Mary the Virgin Church in Ashford.

The Grade I listed church will open its doors to the public to show off the £1.7m renovation project to provide an upgraded shared space in the body of the nave. There will also be a one-day exhibition of its unseen areas. The church is in the centre of Ashford, behind the County Square Shopping Centre.

Five gems to discover

Archcliffe Fort, near Dover

Discover the remains of a fortification originally built for Henry VIII in 1539. Over the next 400 years the fort was continually updated until it was disposed of by the War Office in the 1950s. Sections were destroyed by both the railways in the 1920s and by the building of the A20 in the 1990s. The fort is now occupied by St Martin’s Emmaus Community, which moved into the site in 1995 and provides accommodation and workshops where old furniture is recycled and sold. The history of the fort will be told on a self-led illustrated tour. Open Saturday and Sunday.

Folkestone Leas Lift Pump Room

Visitors can see the Victorian reciprocating pumps and other lift machinery not normally open to the public. The lift is the second oldest water balance cliff lift still operating in the UK and is home to one of the Folkestone Triennial exhibits, Martin Creed’s Work No. 1196. Open every day.

Fordwich Town Hall, near Canterbury

Built in 1544 during the reign of Henry VIII, this brick and timber-framed building was once used as a court-room and jail. The town hall is still used by the town council for meetings and it is believed to be the oldest and smallest still in use. An historical audio-visual commentary will be playing in the undercroft throughout. Open every day.

Romney, Hythe & Dymchurch Railway

The railway will be holding twice daily behind-the-scenes tours of its engine shed and workshops at the New Romney station. There will also be the chance to find out about the railway’s part in the Second World War effort and its contribution to the Pipeline Under The Ocean (PLUTO) project. There is also a 1940s exhibition at New Romney Station. Open Saturday and Sunday.

Stoneacre, Otham, near Maidstone

A 15th century half-timbered yeoman’s house, featuring a great hall. The building between Bearsted and Maidstone is surrounded by a garden, orchard and meadows. Open Saturday.

Heritage Open Days take place from Thursday, September 8 to Sunday, September 11. Entry to all the buildings taking part is free but booking is required for some events. For times and details visit www.heritageopendays.org.uk