New London — It’s nestled below the two towering spans of the Gold Star Memorial Bridge with traffic rumbling overhead, bordered by a commercial area.

But the grounds of the historic city-owned Old Town Mill offered a respite for visitors on Saturday, the last open house of the year.

“It’s absolutely beautiful,” said Barbara Pantalone of Mystic, who stopped in for a tour with family members to take in a bit of history and a walk along the newly planted pollinator garden. The garden, which borders the property with flowers and shrubs, was a gift from Thames Valley Sustainable Connections.

Pantalone said the city was lucky that someone had the foresight to keep and maintain the old grist mill, one of the oldest industrial sites in the country. Pantalone’s granddaughter, 9-year-old Tahirih Arzu Pantalone of New London, couldn’t decide which was the best part, the inside with its grindstones that at one time turned corn, wheat and rye into flour, or the working water wheel outside fed by waters from Briggs Brook.

The mill, also known as Winthrop Mill, was opened in 1650 by former Gov. John Winthrop Jr., who founded New London and built a home on the same property. It was purchased by the city of New London in 1892 for $20,000, leased and remained in commercial operation until 1913. It is listed on the National Register of Historic Places and was at one time situated in front of Winthrop’s home.

It still retains some of its original elements, though it has been rebuilt several times — most notably after it was burned with much of New London in a raid by Benedict Arnold in 1781. The city has invested in various repairs through the years, most recently to the shaft of the water wheel, which had been deteriorating. While the wheel works, it no longer turns anything inside.

The mill is the site of the annual Old Town Mill harvest festival, which features free horse-drawn wagon rides, craft vendors, music, kettle corn, apple cider and doughnuts.

City employee Judi Cox, who more often than not is guiding tours at the site, said it is unclear whether the festival will go on as scheduled this year. It is tentatively scheduled for Oct. 31.

Volunteer Jim Diaz-Saavedra, who guided the tours of the mill on Saturday, called the mill “a hidden gem in the city of New London.”

g.smith@theday.com