Sharon’s historic one-room Brick Schoolhouse has been listed on the Country Schools Association’s National Registry as only one of five “Landmark” school buildings in New Hampshire, and the first in the Monadnock region.

Susan Fineman, a founding member and director of the Country Schools Association of America, unveiled a plaque identifying the building as a “Landmark” at a ceremony Tuesday evening.

“We are saying, sincerely, thank you to all of the …