Beneath one of the City of London's least glamorous addresses — an underground car park on London Wall — sits a genuinely ancient survivor: a substantial stretch of the original Roman city wall, nearly two millennia old, standing in the middle of the parking bays.
The wall dates from around AD 200, when Roman London (Londinium) encircled itself with defensive masonry. Much of the circuit survived in some form for centuries, and while large sections were demolished or swallowed by later building, a few chunks remain remarkably intact. This one, tucked behind the parking spaces in the London Wall car park, is protected by a barrier so drivers can — quite literally — park next to Roman history.
It's a quirky quirk of London archaeology: the city has been built over itself so many times that Roman remnants ended up in basements, office foyers and, yes, car parks. The best-known parallel is the stretch of Roman wall displayed in the car park at Tower Hill station, and the London Wall section sits along what was the medieval-and-later street line of the old walled city. Nearby, the recently reopened London Mithraeum (the Temple of Mithras) offers another free dose of Roman Londinium, and the Museum of London's new home at London Wall West continues the story.
Finding it takes a little effort — you'll need to head into the car park itself, and there's even a marked bay that lets you view the wall up close. Video clips circulating online show the weathered stonework looming over parked cars, which makes for one of the stranger photo opportunities in the Square Mile. It's free to see, takes about ten minutes, and pairs nicely with a walk along the remaining wall fragments in nearby Barber Square and St Alphage Garden.
Why bother? Because it's a reminder that London's history isn't confined to ticketed attractions. Some of the most interesting layers of the city are hiding in mundane spots — office courtyards, tube stations, multi-storey car parks — and tracking them down is a free, self-guided way to see a completely different side of the City. History buffs, walkers doing a Roman London circuit, and anyone who enjoys oddball sightseeing will love it. Just check the car park's public access arrangements before you go, as opening hours can vary.