"The Great Elm"

There is a plaque in the grass that you can only see when you're standing on it.

America’s oldest public park originally was used to graze local livestock from 1634 to 1830. The Common became a site for Puritanical punishments, home to a whipping post, pillory, and stocks. Pirates, murderers, and witches were hanged from the tree known as "The Great Elm," (also used as a Liberty Tree type symbol) now gone. Mary Dyer and three other Quakers were also hanged in Boston Neck for their beliefs. A statue of Mary Dyer now stands on the Massachusetts State House lawn. The tree grew older and weaker over time and finally toppled in 1876.

An inscription was placed on the surrounding protective fence in 1854 which is now replaced with a stone plaque in the grass. The old inscription read:

“THE OLD ELM. This tree has been standing here for an unknown period. It is believed to have existed before the settlement of Boston, being fully grown in 1722. Exhibited marks of old age in 1792 and was nearly destroyed by a storm in 1832. Protected by an iron fence in 1854. J. V. C. Smith, Mayor.”

-Source Links-

https://www.hmdb.org/m.asp?m=176868

http://www.celebrateboston.com/ghost/boston-neck-executions.htm

http://www.celebrateboston.com/sites/boston-common-great-elm.htm