Not just an ordinary church
This isn't a church you will pass, but it is quite extraordinary. Here it is on the map, a private road and cul-de-sac in the heart of London. First, it stands in a piece of London that was actually part of Cambridge until around 50 years ago - Ely Place. It is the oldest Catholic Church in London, dating from around 1200. I have been there for midnight mass on Christmas eve (not this year) and you can almost hear the monks shuffling on the flagstones, a recommended experience. Second, it was one of the last places in London where you could seek sanctuary - whatever the cause or crime, you could avoid capture by entering this church. I will try to follow up with a photo from the interior some time.