Behind the mass of high-rise buildings and sprawling network of roads in Croydon's town centre lies a colourful past.

Borough archivist Chris Bennett will be leading a series of historical walks around the town taking in some of the key sites that have played a part in Croydon's past as part of Heritage Open Days.

The walks will be a unique opportunity for people to visit some of the borough's hidden treasures buildings not normally open to the public as well as hearing some of the stories that have helped shape Croydon's heritage.

Starting at the Clocktower the two-hour tour will head to Surrey Street to take in the sights and sounds of the modern-day market.

Croydon has had a royal charter to hold a market since 1276 and the talk will also reveal how the area has changed over the years.

Next stop will be the Water Tower, a mid 19th century water pumping station which lies behind Surrey Street. Often mistaken for a castle, the tower stands alone amid the houses and blocks of flats that now surround it.

Other sights included in the tour will be Croydon Parish Church. There has been a church on the site in Church Street since the 15th century. It is the burial place of six Archbishops of Canterbury and monuments to Archbishops Sheldon and John.

The church was almost destroyed by fire in 1867 but was rebuilt by Sir Gilbert Scott. Tours of the church and its bell tower will run during Heritage Open Days.

Then the tour will move on to one of the most important buildings in Croydon the Old Palace.

Mr Bennett says: "The Old Palace was the out of London residence of the Archbishops of Canterbury and is now a renowned girls' school."

From there the tour will stop in Tamworth Road to remember the fateful night on November 2, 1952, that Derek Bentley and Christopher Craig were caught trying to break into a warehouse.

Housing now stands in place of the warehouse but the case is remembered as one of the biggest miscarriages of justice in British history.

Nineteen-year-old Derek was unarmed and was being held by a policeman when he is alleged to have called out to his friend, Let him have it, Chris'. Christopher shot and killed PC Sidney Miles.

On January 28, 1953, Bentley, who had a mental age of 11, was hanged for supposedly inciting his accomplice to fire the fatal shot.

Christopher Craig, who was 16 at the time, was jailed. He has since been released.

Derek's sister, Iris, spent the rest of her life campaigning for the conviction to be quashed and a pardon granted. She died in 1997, less than a year before her wish was granted.

The tour will also look at some of the contemporary landmarks which dominate the Croydon skyline.

The guided tours will be held at 10.30am and 2pm on Saturday and 2pm on Sunday. To book your free ticket go to the box office at Croydon Clocktower.

Details of the other buildings open during Heritage Open Days visit the Tourist Information Centre in Katharine Street or pick up a leaflet at the borough's libraries.