The Mayflower actually first dropped anchor not at Plymouth Rock but off the sands of Cape Cod. Pilgrim Monument, a 252-foot granite tower in Provincetown, commemorates its arrival. Five weeks later, the Pilgrims weighed anchor and sailed across Cape Cod Bay toward Plymouth.
In 1774, the rock broke in two when Plymouth residents sought to move it to the front of the local meetinghouse as a symbol of liberty. In 1880, the two pieces were reunited, and the date 1620 was carved into its face.
Geologically, Plymouth Rock, composed of Dedham granodiorite, is a glacial erratic.
In 1741, Thomas Faunce, then 95, related that his father, who’d known some of the Mayflower passengers, had told him (erroneously) that Plymouth Rock was where the Pilgrims had first set foot in the New World, though the Pilgrims’ own accounts of the 1620 landing don’t mention any such rock.
Plymouth Rock has occasionally been vandalized. On Thanksgiving night 1997, following a clash between police and Native American protesters, someone heaved a balloon filled with red paint at it. And in 1998, a 16-year-old Plymouth youth was charged with spray-painting the words “Made in Taiwan” on the rock and “Peanut is yo daddy” on the portico interior.
Rumors abound that pieces of Plymouth Rock have turned up in stone walls, as doorsteps, and, in one case, as a weight atop a barrel of corned beef at a local market.
In 1920, Plymouth Rock was relocated to the shore. A Roman Doric portico designed by McKim, Mead & White was erected over it, with metal grates at sea level to let the tide wash over it.
Close to one million people a year visit Plymouth Rock at Pilgrim Memorial State Park in Plymouth, Massachusetts.
In 2006, the Troll Colony Memorial, a satirical Web site about life in Plymouth, reported that pirates in kayaks had stolen the rock and towed it to Manomet Point–where seals were sunning themselves on it while the perpetrators waited for a $1 million ransom.Plymouth Rock may have originally weighed as much as 20 tons. The visible top third weighs approximately 4 tons; the buried bottom weighs 6 tons, meaning that Plymouth Rock is probably about half the size it once was.
There’s a Plymouth Rock on the Red Planet. On June 7, 2004, NASA’s Mars Exploration Rover Spirit took a photo of the 35×20-inch chunk of basalt, informally named for America’s most famous rock.