It was first shaped thousands of years ago by a huge chunk of ice which broke off a retreating glacier.
When the ice finally melted, it left a steep-sided pit that geologists call a kettle hole.
In 1645 the first settlers from England named the water at the bottom of the kettle hole Frog Pond.
Here they watered thousands of their sheep, which grazed on the ridge above.
The common land around Frog Pond was dug out for its sand and gravel.
It also became the site of a windmill (the millstone lies near the path along the south rim) and the long wooden shed of a ropewalk bordering High Street.
In 1774 the southerly side was leveled to form a Training Field for the militia companies which soon would fight in the Revolutionary War.
After the ropewalk was torn down, Nathaniel Tracy, merchant and privateer owner, was authorized in 1779 to plant shade trees on the vacant site.
The shift from gravel pit to park continued in 1800.
Captain Edmund Bartlet and friends undertook to fill an unsightly gully.
They also converted the ropewalk site into a promenade, patterned after London's famous Pall Mall.
It was named the Bartlet Mall.
In 1834 volunteer workers extended the walkway around the western rim above the pond.
They also implanted turf in the embankments above and
below the path.
Professional landscaping (plans by Charles Eliot) was sponsored in 1889 by the Mall Improvement Society, which left the paths and lawns much as you see them now.
Today, the City Improvement Society and other citizens continue to keep an eye on the area and to offer a helping hand.
For two centuries the Mall has been a place for special activities - skating, sliding on snowy slopes, picnicking, community celebrations, festivity, quiet contemplation.
All of these doings have made the Mall a special place for all of us.