Visible from the Winslow road several miles away, it looks like a huge Norman castle, set against the background of the Chilterns. But instead, it’s a 1960s building right in the centre of Aylesbury.

The coat of arms on London Road Bridge is made from Coade stone, a ceramic material.

You might think that you know Buckingham very well, but here’s a few things you just might not know and can find on a walk that's just a mile and a half long.

Park at Cornwall’s Meadow. It has plenty of spaces and costs just 50p for three hours. It’s on the South side of the Stratford Road end of the High Street. From there, take the footpath through the woods at the opposite end from where you drove in. When you cross the footbridge over the River Great Ouse, turn right.

Walk past the skate park and playground, and you’ll find yourself at the end of London Road Bridge.

Built mostly at the expense of the Marquis of Buckingham, the bridge has his coat of arms in the centre of the North side, above the river arch. You might have seen it if you’ve walked across the footbridge that runs close alongside; it’s close enough to touch.

Near the entrance to the new theatre in Aylesbury is a statue of Ronnie Barker, as he looked when he played the prisoner Fletcher in the TV series Porridge, between 1974 and 1977. He considered Norman Stanley Fletcher to be his finest creation.

Born in Bedford in 1929, Ronald William George Barker was living in Oxford in 1948 and working in a bank there. He took a trip to Aylesbury to see a play at the Market Theatre, where the Manchester Repertory Company were Performing.

The Market Theatre was off the Market Square, and behind The Green Man pub. It's gone now.

Back home, he wrote to the company asking for a job and enclosing a photograph, but didn’t receive a reply. He wrote to them again asking for the photo back, and they offered him an audition. At the audition, he was hired on the spot.

His first role was in J.M. Barrie’s comedy play Quality Street. That was in November 1948; he was nineteen.

Once Ronnie Barker had performed in two more comedy plays he realised that he wanted to become a comic actor. In 1956 he made his first radio appearance in the sit com The Floggits. Later he played Able Seaman Fatso Johnson, in the excellent long running comedy series The Navy Lark.

This radio programme ran from 1959 to 1976, and he played a total of 40 different characters.

Many people don’t realise that he played another role in Porridge, too; that of the judge who sentences the “habitual criminal” Norman Stanley Fletcher to five years in the opening credits. Ronnie Barker played a huge variety of radio, TV, and film roles over the years; he was a man of great talent. He passed away aged 76, in October 2005.

If you want to hear how good he was in his younger days, The Navy Lark is often broadcast on Radio 4 Extra. See if you can spot which characters he plays; it’s not as easy as you might think.

I’ve written about some of the other statues in Aylesbury; there's lots of them:

Ziggy Stardust and the Spiders from Aylesbury. David Bowie played in the Borough Assembly Hall, which is what the Market Theatre later became. Standing Square in Aylesbury. A Market Square hero. A Bird From Aylesbury. John Hampden gets the bird.

As a schoolboy, I often went to the post office in Winslow High Street with my Mum. It’s been closed for years now, and instead there’s a post office in the One Stop supermarket, opposite the Square. But the brass letter box in the wall of the old post office is nice and shiny. What’s going on?

Despite appearances, the box is still in use. I visited Winslow High Street recently, and when I came out of the shop, I noticed a woman polishing the box. She told me that her name is Brenda, and she said that she has lived in the town for many years. She told me that because the post office looks deserted, she regularly polishes the letter box so that people realise it is still in use; she does it at her own expense.

I looked at the 1911 building. The windows were dusty, and the vending machine in the window last sold stamps at 5p each. It doesn’t look as though the building is in use, but it’s the local Royal Mail delivery office.

If you are not in when your parcel arrives, this office, at 61 High Street, is where you can collect it. For opening times and information click here. It’s opposite the Co-op.