New York has always been a city of contrasts: modern skyscrapers side by side with historic buildings, visible glamour, and secrets hidden behind ordinary doors. It’s no wonder that series like Only Murders in the Building draw on this imagery, suggesting that inside a luxury apartment building, there could be a clandestine casino hidden in its basements. But does this idea have any basis in reality?

The fate of carriage houses and urban stables

In the 19th century, the city ran on horses. Elite apartment buildings and brownstones had underground areas and carriage houses to shelter coaches and animals. With the arrival of automobiles between 1900 and 1920, these spaces were quickly converted into garages or repurposed as service areas, storage, and even residences. In neighborhoods like the Upper West Side and in landmarks such as The Belnord — the building that inspired the fictional Arconia — this transition was a natural part of urban life.

Illegal casinos: myth or reality?

Here’s where myth and truth intertwine. It’s a fact that New York once hosted thousands of underground gambling spots. Reports from the 1970s describe secret casinos operating in apartments, private clubs, and modest storefronts, always with restricted entry and password systems. During Prohibition (1920–1933), basements also became the stage for illegal bars (speakeasies), strengthening the association between the city and hidden, forbidden activities.

However, there are no concrete records that former carriage houses were turned into clandestine casinos. That connection is more of an urban legend than a documented practice. Gambling houses thrived, yes, but mainly in discreet venues that could quickly reopen after a police raid: apartments, salons, and private clubs.

The allure of the “hidden”

Part of the fascination with these myths comes precisely from the contrast: the same space that once sheltered horses or luxury cars could, in the popular imagination, transform into the stage for high-stakes games. For writers and storytellers, that overlap is irresistible.

So when Only Murders in the Building hints that the Arconia could hide an illegal casino in its basements, the series is not too far from New York’s historical reality. It’s playing with a plausible myth, rooted in a city that has always thrived on secrets behind locked doors.