The case against six people detained after protesting at a council meeting has been discontinued.
The Rotherwas Ribbon was found during excavation work
The six were arrested at a meeting of Hereford County Council in July when they protested to save the remains of a Bronze Age footpath.
Plans to build a road over the 4,000-year-old Rotherwas Ribbon, as it is known, are going ahead.
The Crown Prosecution Service said there was not enough evidence to secure convictions.
The six, Martin Wyness, 49, of Harold Street, Hereford; Jacqueline Tonge, 46, of Bute Avenue, Hereford; David Phelps, 54, also of Bute Avenue; Jane Knight, 55, of Withy Trees, Burrington; Matthew Hatter, 31, of Park Street, Hereford, and Charles Arthur, 30, of The Post Office, Stoke Prior, near Leominster, Herefordshire, were charged with aggravated trespass.
The Rotherwas Ribbons is a series of deliberately fire-cracked stones and was found during excavation work for a new road.