THE secrets of historic buildings in Hampshire will today be opened to for all to see -  FOR FREE.

The county's annual Heritage Open Days returns to cast the spotlight on some of the region's oldest and most iconic sites and locations.

Places opening their doors until Sunday range from Southampton's grand 15th Century Tudor House to the world's oldest bowling green at Old Green in Lower Canal Walk.

Further afield is the stunning windswept 16th century Calshot Castle in Fawley, the Norman St Mary's Church at Portchester Castle and Bursledon Brickworks.

More modern venues are also open for families to view including the Cold War Monitoring Post at Lepe Country Park and Chandlers Ford Library.

Local clubs organisations will also be celebrating the region's history including the Bitterne Local History Society and the WI and there will be guided tours of the Townhill Park House and its Gardens by children from The Gregg School.

Where to visit: Southampton City Council

*Bitterne Local History Society, Southampton, artefacts from bygone Bitterne pre-dating the bypass will be displayed. Volunteers will be dressed in period costumes and there will be a shop front based on former outlets, plus a children's quiz.

The organisation in Peartree Avenue is open from 10am-4pm on Saturday.

*St Denys Church Centre, Southampton The largest unaltered Victorian space in Southampton. Ancient relics from the Augustinian Priory at St Deny will be on show, plus a World War One display and an extensive collection of second hand books and a children’s trail.

The church in Dundee Road, Southampton, will be open from 10am-2pm on Saturday.

*The Old Green, Southampton The world’s oldest bowling green. Members will dress up in 13th Century costumes to the present day for a Heritage Lawn Bowls game and run tours of the clubhouse and archives.

The green in Lower Canal Walk, Southampton, is open from 10am-4pm on Saturday and Sunday.

*Townhill Park House and Gardens, Southampton Dating back to 1856 the house was previously owned by Lord Swaythling and is now The Gregg School. Pupils will lead tours of its 23 acres of grounds and gardens.

The house in Atlantic Park View, West End, is open from 2-5pm on Sunday with the last tour at 4pm.

*Tudor House and Gardens Visitors can explore the 15th Century house and adjoining Norman property dating back more than 800 years.

The house in Bugle Street is open from 10am-5pm on Saturday.

Eastleigh Borough Council *Chandlers Ford Library Library designed in 1981 and features a unique exterior and interior and horse shoe plan. There will be a photographic exhibition and activities celebrating the library's Architectural Interest Award.

- Library in Oakmount Road is open from 9am-7pm today, 9am-5pm tomorrow and 9am-4pm on Saturday.

- Construction club taster sessions from 10am-1pm on Saturday.

- Guided tours of Chandlers Ford led by Hamble Valley and Eastleigh Heritage Guides from 2pm-3.30pm today.

- Talk on Modern Architecture from 2pm-3pm on Saturday.

*Bursledon Brickworks Industrial Museum, Swanwick Hands on activities at the iconic Victorian industry include making your own brick. There will also be historical displays from the museum and other local history societies.

The museum in Swanwick Lane, Swanwick, is open 11am-4pm today and Sunday New Forest District Council *All Saints Church, Fawley, a 12th Century church and churchyard with Jacobean pulpit, stained glass windows, with clergy robes and historic items on display, plus a Waterside Heritage display, The Marsh Lane church is open from 10am-5pm tomorrow and Saturday.

*Lyndhurst Tour of private house containing family portraits, antiques and items of artistic and historic interest.

The house in Lyndhurst runs hourly tours from 11am-4pm on Saturday and Sunday.

Booking required: contact Yvonne.villiers@hfw.com *Calshot Castle, Fawley Constructed as one of Henry VIII' 16th Century coastal defences protecting the entrance to Southampton Water it features barracks, gun room and displays showing its history.

The castle at Calshot Spit, is open from 10.30am-4.30pm tomorrow and Saturday.

*All Saints Church, Marsh Lane, Fawley Twelfth century church and churchyard with Jacobean pulpit, stained glass windows. displays of clergy robes and other historic items of interest.

The church is open tomorrow and Saturday 10am-5pm.

*Lepe Country Park Hidden Cold War History Revealed, Exbury Exhibition of artefacts and organised trips around the Cold War Monitoring Post, plus talks by members of Royal Observer Corps Association.

The park, in Lepe, Exbury, is open from 10am-3.30pm tomorrow and Saturday.

*Bisterne Manor, Ringwood, Family members will lead 90 minute guided tour of the Manor explaining its furniture and pictures.

The home in Bisterne is open from 2.30pm-4pm today and 10-11.30am tomorrow.

Booking required: Contact 01425 478 808 or email northripleyfarm@aol.com Test Valley Borough Council *Romsey Signal Box Historic signal box dating back to 1865, working museum with leavers and bells. Visitors can operate the signal box and see bygone railway items and photographs.

The site in Brick Lane is open noon-5pm on Saturday and Sunday.

*Mottisfont, Romsey Historic 13th century abbey open Saturday 10am-5pm Winchester City Council *Winchester City College, College Street, Winchester Guided hour long tour of college's medieval heart including 14th century gothic chapel today 10.15am-11.30am.

Booking required: call 01962 621209 *Hampshire Cultural Trust, Chilcomb House, Chilcomb Lane,Winchester Chance to have a behind-the-scenes tour of the museum collection and meet the experts tomorrow 9.30am-12.30pm or 1.30pm-4.30pm.

Booking required: call 01962 826700 *Winchester Quaker Meeting House, Colebrook Street, Winchester Chance to see the three story Georgian building which was a private home, then rectory before it was bought by the Quakers in 1973.

House is open Saturday and Sunday 1pm-5pm.

*Chesil Theatre, Chesil Street, Winchester Visitors can hear about set construction, costume design, lighting designs and special effects as well as the history of theatre and church.

The theatre is open Saturday and Sunday 10pm-4pm St John's House, The Broadway off the High Street, Winchester Visitors can find out about one of the oldest buildings in Winchester, with roots back to the 13th Century.

It is open today, tomorrow, Saturday 9am-5pm and Sunday 10am- 4pm *St John the Baptist Church, Winchester Residents can have a look around Winchester's oldest parish church built in the 12th century.

It is open today and tomorrow 10am-5pm, Saturday 10am-6pm and Sunday 11am-5pm *Hinton Ampner, Bramdean, Alresford Country house with art and ceramics collection in historic parkland.

The grounds are open Saturday 10am-5pm and the house 11am-4pm.

*Woodlands House Art collection at the house in Bramdean opening from 10am-1pm tomorrow to 2pm-5pm on Saturday.

Booking required: Contact 017308 23332 or sarah.cowlrick@farmline.com *Hockley Mill, off Church Lane, Twyford Eighteenth century watermill thought to be the last horizontal axil mill in Hampshire. Water power enabled the farm to run a saw mill.

The mill is open on Sunday 10am-4pm.

*Shedfield Old Tower, Church Road, Shedfield Restored 185-year-old tower is all that remains of the original chapel. There will be tours of the building featuring a ground floor exhibition and web cams with owl roosting activities.

The tower is open from 2pm-4.30pm on Saturday and Sunday.

*8 Piping Close, Colden Common, Winchester A 1979 house that has been made 86 per cent carbon saving after an eco refurbishment.

House is open Sunday 10am-12pm / 1pm-4pm. Booking preferred - visit superhomes.org.uk *St Michael & All Angels Church, Bullington Lane, Bullington, Winchester It is open 2pm-5pm on Sunday and local craftspeople will be displaying their work and doing demonstrations Fareham Borough Council *St Mary’s Church, Portchester Tours of the Norman church in Portchester Castle running from 2.30-5pm today, tomorrow and Sunday.

*Castle Street, Portchester Tours down the historic street featuring Georgian and Victorian modern architecture within naval and commercial history.

Tours run from 2.30-3.40pm on Saturday and Sunday.

Gosport Borough Council *Court Barn, Court Barn Lane, Lee-on-Solent Visitors can discover how this 16th century listed building has developed in the past 400 years from a court barn to a farmer's family home to today's use as a social venue for a Conservative club.

It is open today, tomorrow and Saturday for tours at 9.30am, 10.45am and 2pm.

*Coastwatch Lookout Station, Beach Road Car Park, Marine Parade East, Gosport Residents can drop in to talk to the watchkeeper about their voluntary work from today to Sunday 10am to 7pm.

*Lee on Solent historic waterfront walk Residents can take part in 90 minute walk to learn more about the area's history for the last 130 years, meeting at Elmore car park, Marine Parade West, at 10am today through to Sunday.

*Methodist Church Hall, High Street, Lee On The Solent The WI Inspiring Women for 100 Years - three Lee on the Solent institutes host displays and exhibitions including handicrafts and crochet poppies for Remembrance Day.

Runs tomorrow from 10am-3.30pm.

*St Mary the Virgin Church, Rowner Lane, Gosport There will be an information board about the church's architecture and there is a tour on Sunday at 3pm.

*Fort Brockhurst, Gosport Visitors can meet the curator to hear about historic objects from English Heritage's extensive reserve collection today 11am-2pm.

They can also find out about its military heritage and try on genuine military uniforms as well as seeing art made specially for the fort on Saturday and Sunday 11am-3pm.

*Fort Rowner tour at HMS Sultan, Military Road, Gosport Residents can tour around one of the Palmerston Forts built to defend Portsmouth from the French.

Visitors can come Saturday or Sunday 9am-1.30pm and booking is required through Gosport Tourist Information Centre *Gosport Airfield and Marine Engineering Museums, HMS Sultan, Military Road, Gosport The museums are open Saturday and Sunday 9am-1.30pm. Booking required: call 023 9252 2944 *HMS Sultan, Gosport Residents can get a conducted tour around the different aircraft types used for training at HMS Sultan with aircraft flown by the Royal Navy from the 1960s onwards on Saturday and Sunday 9am-1.30pm.

*Isolation Hospital, Gosport Residents can tour the former military isolation hospital for the sick built in 1898 and extended in 1918 and hear about its history.

Tours run today to Sunday 11am and 2pm meeting at the gate of Don Styler's Physical Training Centre, in Monks Walk.

Booking required: call 023 9252 2944 *Diving Museum, Stokes Bay Road, Gosport Residents can find out more about diving over the last 100 years at the museum which is open today and tomorrow 11am-4pm.

*The Secrets of Stanley Park Local historian Lesley Burton will be doing a historic walk along Stokes Bay seafront and into Stanley Park at 11am on Sunday starting and ending at No 2 Battery, Diving Museum, Gosport.

Booking required: call 023 9252 2944 *Bay House School, Gomer Lane, Gosport School will open its doors on Saturday 10am-4pm *Residents can explore the heritage of Bury Road and Stoke Road, Gosport with local historian Lesley Burton starting at the War Memorial Hospital Garden and ending at Walpole Park, starting at 5pm today.

Booking required: call 023 9252 2944 *Anns Hill Cemetery, Anns Hill Road, Gosport Residents can take a guided walk around the Victorian cemetery and learn about its history.

Walks are tomorrow and Sunday 11am and 2pm and Saturday at 11am.

*Air Raid Precaution Bunker, The Avenue, Gosport Residents have a chance to see the only surviving Second World War Air Raid Precaution Bunker and Civil Defence Centre in Hampshire with tours today and tomorrow at 11am and 2pm.

Booking required: call 023 9252 2944 *Musical Memories at Thorngate Halls, Bury Road, Gosport Residents have chance to see a unique 1934 3 manual Compton Cinema Pipe Organ built to provide music and sound effects for silent films of the 1930s.

It will be on display today and tomorrow 10.30am-4.30pm.

*St Vincent's College, Forton Road, Gosport Chance to see museum and have a tour of the college which trained boys for the Royal Navy from 1927 to 1968.

Runs today until Saturday 10am-4pm and Sunday 10am-3pm.

For more information see heritageopendays.org.uk.