Every New York City history buff knows about the Commissioner’s Plan of 1811 in which the street grid of Manhattan Island was laid out by John Randel, Jr. who was given the task in 1808. Randel spent the next few years surveying the island and positioning either metal bolts or marble “monuments” to mark the position of the future street intersections. A few of these bolts still exist in the original location that Randel himself placed them. I have the honor of having located one but am also abide by the honor code of those who have found them to not publicize their exact location in order to avoid bad things happening to these amazing pieces of New York City history.

During the wonderful Open House New York event in 2018, the full original map of the Commissioner’s Plan was on display at the Office of the Borough President.

The great “Atlas Obscura” posted a great article about the bolts and the crazy people like me, which you can read here.
Below are some great resources and stories of the bolts and the Plan itself.