Photo by New York World-Telegram and the Sun Newspaper Photograph Collection via Library of Congress

New York City is one of the most publicized and written about places in the world. Between New York City’s relatively short history (compared to historic European cities) and the sheer quantity of literature written, it may seem as though every nook and cranny of the city has been discussed. However, the city still has its fair share of mysteries that are yet to be solved. Some of them pertain to murders and disappearances while others came about during the city’s ever changing urban landscape.

Here are 10 New York City’s unsolved mysteries.

10. The NYC Heiress who Vanished From Fifth Avenue, Never to be Seen Again

dorothy-arnold_nyc_untapped-cities_shervinImage from Wikimedia Commons

On December 12, 1910, a wealthy socialite stepped out onto the sunny streets of Fifth Avenue–only to disappear later, never to be seen again. Dorothy Arnold, the daughter of a wealthy cosmetics and perfumer left her family home on Fifth Avenue around noon. After running a few errands, she ran into a friend outside a bookstore at 2 p.m with whom she had a short conversation; that was the last time anyone saw of her.

What followed was countless man-hours by the police and family, tracking her last moves on the final day of her vanishing, and a frenzy of attention by newspapers around the country. Newspapers followed the case and the seemingly endless bevy of vague leads and tips day-by-day. And yet, despite the immense publicity that the case engendered and the prolonged investigation which lasted for years, no concrete theory was ever established to justify her disappearance.

Dorothy’s disappearance was noticed a few hours later when she was absent from dinner. Yet, Being the daughter of an affluent family, and thereby hoping to avoid unfavorable publicity, the family kept her disappearance from the police and opted to hire their own investigator. After six weeks however, despondent and desperate, they finally went to the police for help.

The entailing police investigation was thorough, with her activities leading up to her disappearance being retraced and scrutinized. Dorothy Arnold lived a busy social life that included many potential suitors–many of whom were taken in for questioning, all to no avail. Given the Arnold family’s social status the case elicited international attention and soon leads came pouring in from all around the country and globe–for years. And yet, none of them amounted to anything.

In early 1911, a shop owner claimed that he’d spotted Dorothy Arnold buying men’s cloths for a disguise and inquiring about a steamer fare. Reports came in of her having been spotted in Italy, and later in Chile, and a flurry of sightings in other countries and U.S cities–all of which amounted to nothing.

Perhaps one of the more feasible leads was that of a prisoner in Rhode Island who claimed he’d been hired to help bury a wealthy woman in a cellar in December 1910, a claim that never panned out either. Her father though, after years of hoping against hope, came to believe that she’d been kidnapped and murdered, a belief that he held onto until his death.

After both of Arnold’s parents died, the family lawyer went public with his own theory: Dorothy had killed herself because of her failure as an aspiring writer. Yet, the lack of discovery of a body puts a major dent in that theory as well as the others.

While this is a story that is unknown to the typical New Yorker, at the time of investigation the case was known across the country, and was covered by all–from the small-town papers to the major metro editions. As the Pittsburgh Press later opined, “It was the really great search of the age, and one that did much to develop modern newspaper police coverage.”