What Is The Oldest Building In London

So, picture this: I’m wandering down a narrow street near Tower Hill, dodging a tourist with a selfie stick, when I spot a tiny, grimy-looking church squeezed between glass office blocks. It looks so out of place, like a hobbit house in a sci-fi movie. I duck inside, and the air smells of old stone and incense—and it hits me: this building has been standing here for nearly 1,400 years. That’s older than the Tower of London. Older than the Magna Carta. Heck, it’s older than most countries. And it got me thinking: what is actually the oldest building in London?

Spoiler alert: it’s not the Tower of London. Sorry, beefeaters. The honor goes to All Hallows-by-the-Tower, a church tucked away on Byward Street (yes, right next to that famous fortress). The core of this building dates back to 675 AD, which means it was built when London was still a scrappy Saxon settlement called Lundenwic. That’s mind-blowing when you realize the Normans didn’t even show up for another 400 years.

Why All Hallows-by-the-Tower Is the Real OG

Here’s the kicker: you can actually see the proof. The church has a small museum in its crypt—and no, not the spooky kind with skeletons (sorry, ghost-hunters). The crypt contains a Saxon arch made of Roman bricks, reused from the old Londinium ruins. Imagine that: Roman bricks recycled into a Saxon church, like ancient upcycling. That arch has seen everything—Viking raids, the Great Fire (which almost got it), and the Blitz, where a bomb actually hit the church but left the core standing.

And it gets juicier. This church is where Samuel Pepys famously climbed the tower to watch the Great Fire of London in 1666. He wrote in his diary, “I saw the fire grow… and, the wind blowing, it did spread.” He was standing in a building that was already 1,000 years old. That’s like us watching a disaster from a medieval castle and tweeting about it. Perspective, right?

But Wait—What About the Roman Stuff?

I know what you’re thinking: “What about the Roman wall? Or the Temple of Mithras?” Good points, curious reader. The London Wall is older—it dates to about 200 AD—but it’s a wall, not a building. The Temple of Mithras (from 240 AD) is technically a building, but it was reconstructed in the 1950s on a different site. So it’s more of a replica than the real deal. The oldest continuously standing building? It’s All Hallows, hands down.

The White Tower, the oldest building at the Tower of London

There’s also the White Tower inside the Tower of London (built 1078). That’s a baby compared to All Hallows. Even Westminster Abbey (built 1245) is a newcomer. So yes, a humble parish church beats them all. Sometimes the quiet ones win.

The Anecdote That Makes It Real

When I visited, an old volunteer named Margaret told me a story. During WWII, a bomb fell through the roof and landed in the churchyard, but didn’t explode. The soldiers who defused it found Roman pottery lodged in the crater. “That’s London for you,” she said, shrugging. “You dig a hole, and you find history.” That’s the charm of All Hallows: it’s not a pristine tourist trap. It’s a living church with cracks, scars, and a Sunday service where you can hear the bells of the Tower across the street.

Living History: A Guide to London’s Ten Oldest Buildings - Londontopia

Honorable Mentions (Because You’ll Ask)

If you’re a stickler for “building” meaning “still in original use,” then St. Pancras Old Church (built 314 AD? Maybe?—it’s complicated) is a contender. But historians argue that the current structure is mostly 19th-century rebuild. The Guildhall (1411) gets an honorable mention for its stunning crypt. And St. Bartholomew the Great (1123) is a beauty, but it’s still 400 years younger than All Hallows.

So next time you’re in London and you see a building that looks too old to be real, take a closer look. It might be the city’s quietest, oldest secret. And if you go to All Hallows, say hi to Margaret for me—she’s the one with the sparkle in her eye and a story about Roman bricks.

Just don’t ask her about the ghost. She’ll tell you there’s no such thing—but then she’ll smile. And that’s the oldest trick in London.