India, with its rich and long history, is full of mysteries. Perhaps none is as puzzling as what happened hundreds of years ago at a royal city in Rajasthan, now under excavation.

Where is everyone?

Bhangarh inhabited since prehistoric times
Whatever happened here in the Aravalli hills, a line of peaks stretching more than 500 kilometers through Rajasthan, fascinates and frustrates historians and archaeologists.

Few facts are certain many generations later.

Experts believe that Bhangarh, apparently inhabited since prehistoric times, was built into a robust royal city in the 16th or 17th century.  

Where cows graze and tourists ponder ruins, a prosperous Mughal Empire medieval city of 10,000 residents once stood.

There were grand palaces, busy bazaars, well-tended gardens, revered temples and refreshing bathing pools.

And then, inexplicably, it was deserted suddenly, with perhaps only the local monkeys remaining behind.

Historians and residents speculate

Only the local monkeys remain
Some historians speculate the city's occupants fled or were slain in a military battle. Others mention the possibility of a plague or famine.

The area's residents have their colorful theories - all centering around the story of the virtuous, beautiful Bhangarh Queen and a lecherous wizard who desired her. His attempts to seduce her with a magic potion failed. Some say it was he who then cursed the royal city.

Another version, shared here by a local man, attributes Bhangarh's downfall to the object of the sorcerer's desires, the queen, who was also skilled in tantric magic.

One man explains, "Old timers say it was the queen who applied the curse and that the morning after she left, the city would be destroyed and everyone would vanish."

While the nearby villagers tell varying versions of the tale, passed down from generation to generation, one aspect is consistent: Bhangarh, they say, is a ghost town, haunted by spirits of the dead.

Another man says, "It is said that at night ghosts come out. It's a scary place."

Yet another man comments, "It is haunted and deserted - all because of the black magic."

There are the occasional visitors who would dare share this space after dusk when the bats take over to try to either prove or debunk this ghost story, but such attempts are forbidden.

The Archaeological Survey of India, which controls the site, expressly forbids visitors between sunset and sunrise.

That prohibition has only made the ghost town more enticing to visitors from India and abroad - but only during the daytime.