CITY attractions will reveal their secrets when their doors are opened to the public at the weekend.

On Saturday and Sunday visitors can discover Oxford’s hidden gems by getting into hundreds of places for free as part of Open Doors Weekend.

There are more than 150 venues taking part, from university colleges to museums and churches.

At Oxford Castle, detectives will be creaking open the door of Oxford’s old prison between 11am and 4pm on Saturday.

Families will be able to meet police officers, see how forensic experts look for murder clues and learn about the man who invented fingerprinting.

Oxfordshire Commander, Chief Supt Brendan O’Dowda, said: “It’s an ideal opportunity for us to open our doors to the public and let them know what we do.

“I used to visit the prison and interview many suspects there.”

The Town Hall and the Museum of Oxford will also open their doors. On Saturday and Sunday there will be a tea party, the chance to take a seat in the historic court room, and a showcase of some of the city’s greatest treasures and paintings.

There will be an exhibition on the revamp of the museum, which will include a tourist information centre and café.

Town hall manger Lidia Pocock said: “It is a great opportunity to visit buildings you may have walked past in your lunch hour and never been into.”

The events include a Town Hall Treasure Trail from 10am on Saturday and a Mad Hatter’s Tea Party in the main hall on Saturday afternoon.