A vertical crack slices the wall of an old pub, letting in cold drafts and attracting an unusual bit of attention. But the building owners won’t be patching it up anytime soon. According to a plaque beside the slit, the narrow gap is the smallest window in England.

A porter once waited inside the building, peering through the crack. It wasn’t a glamorous job, nor was its purpose to gather any secret intel about the happenings on the street. The watcher behind the wall was a dutiful pub employee, keeping a lookout for any stage coaches that may need immediate attention. It was a 17th-century method of ensuring rapid customer service.

It’s hard to tell if the slim opening even classifies as a window, or if it’s truly more of an elongated peephole of sorts. Nonetheless, the site is worth a visit. The building houses the George Hotel, which is thought to be the oldest surviving pub in Hull and dates back to 1683. It’s located on Land of Green Ginger, a quaint street with a fairytale name in the city’s Old Town.