At a large intersection near London's Leicester Square, sharp-eyed pedestrians will be able to spot a mysterious coat hook drilled into a building façade near 5 Great Newport Street. According to Atlas Obscura, the hook was placed there for a very specific group of people—traffic cops.

London's first motorists didn't trust traffic lights. The city installed its first red-yellow-green signals at the junction of St. James's Street and Piccadilly only in 1925, and most major intersections still employed Metropolitan Police officers to direct traffic. At the junction of Great Newport Street, Garrick Street, Long Acre, Cranbourn Street, and Upper St. Martins Lane, cars and carriages depended on a bobby to tell them when to go ahead.

At the time, police officers wore woolen uniforms with capes, even in the hottest months of summer. One of the traffic cops at the intersection, whose name is not recorded, noticed a nail protruding from a construction site near 5 Great Newport Street and hung his cape on it. His fellow officers followed suit as temperatures climbed. When the construction work ended sometime in the 1930s and the nail was removed, the officers petitioned the building's owners to install a permanent fixture.

Today, the ornate iron hook remains drilled into the wall, along with a metal plate reading "Metropolitan Police." It's unclear whether those who are not police officers can drape their jackets on it.

The unique piece of street furniture has outlived the need for traffic-directing bobbies, but it remains a beloved part of London's transportation history. Allegedly, the hook is one of the 20,000 points of interest to be memorized for The Knowledge, the infamously difficult test one must pass to become a London cab driver.

[h/t Atlas Obscura]