EC4N centres on Cannon Street and Walbrook, close by Mansion House and the southern reach of Queen Victoria Street. Set into a wall on Cannon Street sits a block of limestone known as London Stone, and nobody has ever definitively explained what it originally was. One theory connects it to a Roman governor's palace once thought to have stood nearby. Whatever its origin, people have treated it as significant for centuries. In 1450, the rebel leader Jack Cade struck it with his sword while claiming authority over the City.

A popular saying ties the stone's safety to London's own fortunes, but that saying isn't the ancient relic it sounds like. Research has traced it only as far back as 1862, invented long after the stone itself first appears in written records. The stone has survived the Great Fire and the Blitz regardless, and today sits behind glass at 111 Cannon Street, largely unnoticed by the thousands who pass it daily.

A Temple Nobody Knew Was There

A few streets away, on Walbrook, an actual Roman temple lay completely forgotten until construction workers uncovered it in September 1954. Built around the mystery god Mithras in the third century AD, it became an overnight sensation. Queues reportedly reached 30,000 people a day over a fortnight, with the site making front-page news.

Construction pressure won out in the end. The temple was dismantled and rebuilt roughly a hundred metres away in 1962, on a car-park rooftop, and quietly became known as one of London's more disappointing attractions. It took until 2017, and a decade of work funded by Bloomberg, for the temple to return close to its original spot, seven metres below street level, as a free public museum.

One object nobody could identify, one building nobody expected to find: this postcode has a habit of holding onto things worth keeping, long after it would have been easier to let them go. We approach a lock the same way. If it can genuinely still do its job, we'd rather repair it than simply swap it out.