How far away is it?

I took this photo in London, England, the UK. This was my first photo on the following morning after my arrival. The nearest red telephone box from the previous night's pub. I was walking toward Baker Street in Marylebone district from my hotel. My flight from Bangkok, Thailand to London flew in London Heathrow Airport, but my flight from London to Tel Aviv, Israel would depart from London Luton Airport. Luton Airport is located 57 kilometers away from Central London. I couldn't possibly think about taking a cab ride to the airport, so I made a bus reservation in advance. The bus company was named easyBus and their buses run in between Baker Street and Luton Airport so many times a day. I just wanted to check how long does it take to walk from my hotel to Baker Street. It was a 20-minute walk or less. From Baker Street tube station I took a tube and went to see the London Eye.