The Old Lyme South Green is a small (quarter-acre) triangular-shaped greensward located at the intersection of Lyme Street and Shore Road. Its present condition gives no clue to its illustrious past.

The lawn slopes gently down from the road and is crossed by driveways that provide access to homes fronting the green. Deep ruts and trampled grass are a result of automobiles failing to negotiate the sharp turn on Lyme Street and driving onto the green. Also contributing to the poor condition of the green are tour buses that use the grass area as a turnaround and members of the First Congregational Church, who use it as an overflow parking lot.

There are no paths, monuments, curbing, or trees on the green.

The southern portion of the green now belongs to the Gertrude Barney estate (Marvin House) and is inaccessible to the public. The Old Lyme Conservation Trust is negotiating to buy back the property so that South Green can once again be whole.

Many fine historic buildings surround the green. The First Congregational Church faces the green at the southwest corner of Ferry Road. The church is a replica of one that was destroyed by fire. The original church was designed by Col. Samuel Belcher and was based on plans for a London church designed by Christopher Wren. The replica was designed by New Canaan architect Ernest Greene and was dedicated on June 19, 1910. Notable features of the church include a four-column Ionic portico, a delicate cornice, and a four-stage steeple. South of the green is the Marvin House, dating from the first quarter of the 19th century.

The McCurdy House, which faces the First Congregational Church at One Lyme Street, was built around 1700 and is a good example of Colonial architecture. During the Revolutionary War, General George Washington and General Lafayette were guests here.

Facing the green, to the west, is the Ludington House. Built in 1893, on the site of the pre-Revolutionary Parsons Tavern, it is in the Colonial revival style. The five-bay house features a curved portico and a hip roof. An ornamental picket fence separates the front yard of the green. In the garden is a large rock from which George Whitefield, a noted 18th century evangelist, preached a sermon.