Few people dared to enter the Walled City in Hong Kong’s Kowloon district. As a haven for gangs, drugs and brothels, with its dark alleyways and damp, cramped walkup buildings, it was Hong Kong’s most notorious slum.

The Walled City was technically an ungoverned Chinese territory under British rule, and at its peak home to about 35,000 people. While both governments turned a blind eye to the three-acre enclave – the most densely populated place on earth – it grew to become a virtually lawless labyrinth where poor families lived next door to opium parlors, whorehouses and gambling dens run by the triad syndicates.

Although it was torn down by the Hong Kong government in 1993 and replaced by a park, the Walled City’s mystique still keeps people intrigued. Including people in Japan, where a replica ohas been created inside a Kawasaki warehouse, grime and all, but no opium.

Anata no Warehouse, a few minutes walk from Kawasaki Station, is the creation of a Japanese games company that decided the Walled City would make the perfect backdrop to a video-game arcade. Tokyo-based photographer Said Karlsson shot images from outside and inside the game center, which spans four floors, and has all the latest titles, a dedicated retro game corner and a floor with darts and billiards.

Most of Tokyo’s hundreds of game centers are pretty bland when it comes to interior design. Anata no Warehouse is the notable exception, where the gritty ambiance of the Kowloon Walled City has been faithfully recreated.

The Wall Street Journal made a short documentary about the Walled City. For the best Hong Kong movie to capture the enclave’s unique history, dig out director Johnny Mak’s Long Arm of the Law, a 1984 classic about a hapless gang of robbers from China.