HIDDEN rooms and historic buildings in Oxford will throw open their doors to thousands of visitors this weekend.

Oxford Open Doors has returned for its 11th year, offering special access to some of the city's most treasured landmarks.

Museums, libraries and buildings old and new will reveal their secrets, including some not normally open to the public.

Sites are free to explore and Oxford Preservation Trust, which runs the event in partnership with Oxford University, has a stall in Cornmarket Street with information about where to go.

This year's theme is Extraordinary People, with many places having a connection to famous characters - including Harry Potter filming locations at Oxford colleges, the former home of CS Lewis, and the Painted Room apparently visited by Shakespeare.

Oxford Castle has been busy with visitors as entry to the museum and Castle Mound are free.

Eleanor Dix, from Kidlington, who works in publishing, was at Oxford Castle with husband Chris and daughters Matilda, five, and Jessica, two.

She said: "We are really enjoying Open Doors - Matilda has been trying out the archery and it's a good chance to climb the Mound.

"We are also hoping to visit Lincoln College and and the swing bridge at Rewley Road - we try to see as many things as possible."

Molly Moore, 22, an Oxford Castle guide, also a Masters student at St Catherine's College, said: "The Castle tower is over 1,000 years old - there is so much history to see here.

"Among the first prisoners in 1216 were students who got locked up after getting drunk."

Madeline Robinson from Colchester was joined by her family on the Castle Mound when they visited Oxford Castle.

She added: "We also got a fascinating insight into work going on at the university's joinery department."

David Kyffin, former landlord of the Kings Arms pub in Oxford, is now a volunteer guide at Oxford Castle.

Dressed as a Royalist to entertain Open Doors visitors, he said: "I've done this for the past three years but it's very busy this year - people are booking for tours right up to about 5pm."

Oxford Mail:

Despite the drizzly weather, there was already a queue at 10.30am this morning for the popular Painted Room in Cornmarket.

For the first time, several tours and lectures will be streamed to online viewers, including live footage from the Pavlova Wind Quintet concert at the Sheldonian Theatre. 

Venues open today include:

- Blackfriars Priory

- Real Tennis Court, Merton College

- Saïd Business School

- Blavatnik School of Government

- Christ Church

- Greyfriars

- Examination Schools

- New Theatre

- Old Bodleian Library

- Oxford Castle and Prison

- The Painted Room

- Oxfordshire Fire and Rescue Service, Rewley Road station

- Radcliffe Observatory Quarter

There will also be vintage bus rides around the city from Bonn Square, provided by Oxford Bus Museum. 

Click here for the full line-up of events, timings and locations.