Discovering the Posterngate: Lincoln's Hidden Roman Gateway

The Posterngate has to be one of my favourite places in the city, so I have no idea why it has taken me so long to write about it!

Hidden beneath the streets of modern-day Lincoln lies one of the city’s best-kept historical secrets, the Posterngate, a Roman gateway that once served as a vital link between the ancient city of Lindum Colonia and its riverside port. Though thousands of people walk above it every day, few realise that below the corner of Saltergate and Bank Street, under the former Royal Bank of Scotland building, sits a remarkable piece of Lincoln’s Roman past.

The Posterngate dates back to the 4th century AD, when Lincoln was a bustling Roman settlement. It was a functional “postern” gate, a small, secondary entryway set into the city’s defensive wall, that connected the southern edge of Lindum to the nearby River Witham and Brayford Pool. This would have been a key access point for traders, merchants, and soldiers travelling by boat. The gateway, along with surrounding Roman walls and streets, lay buried for centuries until it was rediscovered during excavations in 1973. What archaeologists found was an astonishingly well-preserved section of Roman limestone wall, complete with paved flooring and drainage, all lying beneath 15 feet of modern development.

Visiting the Posterngate today offers an immersive dive into ancient Lincoln. Access is only granted on special open days, typically coordinated by Lincoln Museum or during heritage festivals such as the Lincoln Festival of History. These guided tours begin at the museum and lead visitors down Saltergate to a nondescript door, a literal gateway into the past. After descending a narrow flight of stairs, visitors find themselves face-to-face with the remains of the original Roman gateway. It’s a dimly lit space, creating a dramatic contrast between the ancient stonework and the modern concrete steps used to reach it.

The experience is short but impactful. Guides offer fascinating insight into the significance of the site, explaining how this now-hidden corridor once thrummed with daily life and trade. Interpretation boards and occasional artefacts from the original excavation help bring the site to life. Because tours are limited to small groups, usually no more than 20 people, the visit feels personal and exclusive, a rare chance to connect with history away from the crowds.

If you’re planning to see the Posterngate, it’s a good idea to book tickets in advance, as spaces fill quickly, especially during summer events. Tickets are typically modest in cost, around £7, and the tour is suitable for both adults and children. However, due to the steep and narrow staircase, it may not be fully accessible for those with mobility needs, and visitors are advised to wear sturdy footwear.

Posterngate makes a brilliant addition to a historical itinerary in Lincoln. It's conveniently located just a short walk from the Lincoln Museum, the Brayford Waterfront, and uphill sites like Lincoln Castle and Lincoln Cathedral. For those keen to explore more Roman history, the Newport Arch, the oldest Roman arch in the UK still in use by traffic, is also a must-see and makes a great pairing with Posterngate.

Follow the link to find out more about open days.