OPEN a new door, step over the threshold and immediately broaden your horizons.

That is the invitation from the charity Oxford Preservation Trust, which is organising Oxford Open Doors on the weekend of Saturday and Sunday, September 8 and 9.

The popular event is now in its 11th year, as OPT staff are celebrating the trust's 90th anniversary.

Buildings across the city will be welcoming visitors including some not normally open to the public.

Among the buildings on show will be Christ Church college, with its links to Alice in Wonderland author Lewis Carroll and Harry Potter, along with New College.

Residents can also call in at the Ashmolean Museum, Carfax Tower, the Examination Schools, the University Church of St Mary the Virgin or the Blavatnik School of Government.

Prof Louise Richardson, Vice-Chancellor of Oxford University, said: "The university is widely accessible throughout the year, but we welcome the opportunity Oxford Open Doors provides to open more of our buildings, grounds and collections to new visitors.

"We look forward to welcoming you to the university to learn more about our institution and its people.”

The preservation trust, which helps to runs the Oxford Castle Unlocked attraction off New Road, has been working hard with partners across the city, the university, and the colleges to get doors open and let visitors in to explore.

This year’s theme is Extraordinary People and residents are being encouraged to learn more about buildings and the people who have lived and worked in them.

A spokesman for the trust said: "Over the weekend colourful and real characters will be there to greet and tell their stories at Oxford Castle & Prison opening free throughout the weekend for the first time. The Museum of the History of Science [on Broad Street] will be telling of famous female scientists whilst across the road Tolkien is brought to life at the Bodleian.

"Head down to the New Theatre to see who has trodden those boards and on to the Old Fire Station where an exhibition of Oxford women awaits.

"This year Christ Church is open with its links to Alice and Harry Potter, with New College opening after a long gap and where the films were also made."

The Open doors brochure, with a full schedule of locations and events, is now available in libraries and features a family trail.

There should be something for all ages with Oxford archaeologists on hand at the castle site to tell visitors more about what is below their feet.

Ms Dance added: "This is our chance to celebrate this wonderful place that we all call home and the whole OPT team will be out and about over the weekend.

Some venues will also be open on September 6 and September 7. For full details and to make bookings see oxfordpreservation.org.uk

TEN OF THE BEST

The Ashmolean Museum in Beaumont Street

Carfax Tower

The Kilns in Lewis Close, Headington

The LMS Swing Bridge in Rewley Road

The Commonwealth War Graves Cemetery in North Hinksey Lane

The Bodleian's Weston Library in Broad Street

The Real Tennis Court at Merton College

Blackwell's Bookshop in Broad Street

The Sheldonian Theatre in Broad Street

Modern Art Oxford in Pembroke Street