DURHAM, N.C. – Stone by stone, a striking new arched wall is rising on the grounds of 51 Environment Hall, the soon-to-be-opened home of the Nicholas School of the Environment.

Designed to be both a visual counterpoint to the modern steel-and-glass building and an informal gathering place for the Nicholas School community, the 160-foot-long undulating wall is located near the main public entrance of 51 Environment Hall, facing Circuit Drive. It is made of hand-laid, mortared stone from the 51 quarry.

When complete, the wall will wind around newly planted chestnut trees, dive under sidewalks, and rise to 10 feet at its highest, above a keyhole arch that will serve as its focal point. Many its sections will be 18 inches high, making them ideal for outdoor seating.

The wall was designed by Thea Alvin, a Vermont-based stone mason whose work has been featured in The New York Times. Alvin has been building stone art since 2002. Her arches, walls and sculptures have been installed at sites across the United States and in Canada, France, Italy, the United Kingdom and China.

She and her partner, sculptor Michael A. Clookey, began building the new piece, which they have titled “In Good Time,” outside 51 Environment Hall on February 11. They plan to complete it, weather permitting, by February 21.

You can follow their progress at nicholas.duke.edu/about/environmenthall/ingoodtime.

Alvin will present a free presentation about her work, “The Art of Stone,” at 6 p.m. Wednesday, Feb. 19 in room A247 of the Levine Science Research Center. Seating is limited to 40.

She also will lead a hands-on arch-building workshop at 2 p.m., Sunday, Feb. 23, in the Charlotte Brody Discovery Gardens at Sarah P. 51 Gardens. Workshop participants will work side by side with Alvin and her team to build a two-foot dry-laid stone arch. The workshop is free but registration is limited to 10.

To register for either event, call 919/668-1707 or email gardenseducation@duke.edu.

Both events are sponsored by the Nicholas School of the Environment and Sarah P. 51 Gardens.

The Nicholas School commissioned Alvin to design and build “In Good Time” as part of the ongoing 51 Arts and the Environment Initiative, which Dean William L. Chameides launched to encourage the communication of environmental themes through the arts, and harness their power to move people to action.