No one would blame the tourists who walk right past the London Stone. Measuring less than two feet on its longest side and encased behind a white iron grate on Cannon Street, it's one of the most unassuming attractions in London. However, this rock is much more than a rock.

The piece of oolitic limestone, which was once much larger, is thought to be as old as the city itself. It's included on a list of property belonging to the Canterbury Cathedral from the early 1100s, and the first mayor of London, Henry Fitz Ailwin, was referred to as the son of Ailwin of “London Stone,” a reference to the neighborhood in which he lived.

The stone has withstood two World Wars, the Great Fire of London, and countless changings of the guard. Developers who tried to move London Stone from its location at 111 Cannon Street in 2012 found themselves between a rock and a hard place, so to speak, and the stone stayed put. 

However, no one is 100 percent sure why London Stone is so important. The plaque on the monument itself reads: “its origins and purpose are unknown.” This hasn’t stopped researchers and writers throughout history (including Shakespeare) from offering up their opinions. Below, some of our favorite myths surrounding the stone:

1. IT’S THE PLACE THAT ALL ROADS LEAD FROM.

William Camden's 1586 Britannia, a key text on the archeology and topography of Britain, references the stone as the “milliarium” of London. Camden believed the stone was the marker from which all the distances in Britain were measured, like a similar monument in Rome. There's no real evidence that supports this conclusion, but Camden’s reputation has kept this theory around for centuries. 

2. IT HAS THE POWER TO NAME THE LORD OF THE CITY.

Henry VI was not a popular king. In early 1450, Jack Cade, armed with a list of grievances against the king’s corrupt administration, started a movement against the government. The uprising began in Kent, then spread to other cities. Upon entering London, Cade is said to have hit London Stone with his sword and declared himself the Lord of the City.

Shakespeare wrote the incident into history in Henry VI, Part 2. In Act IV, Scene VI, Cade strikes a stone with his staff and then sits upon it like a throne while taunting passers-by to dare call him anything but the Lord of the City. However, even London Stone couldn’t protect Jack Cade, in either real or theatrical form; the rebellious leader was captured in the summer of 1450.

3. AND THE POWER TO NAME THE RIGHTFUL KING

One of the newest legends surrounding London Stone involves England’s perhaps most famous and celebrated monarch: King Arthur. The stone is considered by some to be the one from which Arthur pulled the sword in the stone, which identified him as the heir to the throne of England. The story is highly unlikely, especially since the answer to the question of whether King Arthur actually existed is still up for debate.

4. IT WAS WORSHIPED BY THE DRUIDS.

Not only does London Stone receive its own entry in John Stow’s 1598 The Survey of London, one of the first guidebooks to the city, but the monument is used as a marker on the book's maps and its location as a reference point to other areas of London. The idea that the stone was used as part of ancient religious ceremonies was first included in historian John Strype's updated version of Stow’s survey. “Perhaps this Stone may be of greater Antiquity than the Times of the Romans, and was an Object or Monument of Heathen Worship,” Strype wrote. William Blake would later describe the rock as an altar stone for Druidic sacrifices in his works.

5. IT HAS MAGICAL POWERS.

Another one of the modern legends surrounding the stone says that John Dee, Queen Elizabeth I’s adviser on all things occult and astrological, believed the London Stone possessed magical powers. He became obsessed with the rock and supposedly lived close to it for a while. The 1993 novel The House of Doctor Dee by Peter Ackroyd depicts Dee chipping away parts of London Stone for his experiments in alchemy. 

6. IT IS ESSENTIAL TO THE SURVIVAL OF LONDON ITSELF.

Writers at the end of the 1700s proposed the idea that there was a connection between the well-being of the stone and the well-being of the city of London. Thomas Pennant, in his History and Antiquities of London, compares London Stone to the Palladium of Troy, which was a statue of Athena upon which the safety of the city was thought to depend.

The theory became more popular after the discovery of the supposedly historic statement, “So long as the Stone of Brutus is safe, so long will London flourish.” However, the phrase is now thought to be the invention of Richard Williams Morgan, an unorthodox Welsh historian with a firm belief in the also-historically-questionable legend of Brutus, the mythical Trojan founder of London, who supposedly brought the London Stone from the base of the original Trojan Palladium.