The Commons is divided into two distinct areas by a wide pass. The first area of approximately one hundred acres is due north of the village while the second much smaller area is called the East or Off Commons. Much of the village of Duleek is situated in the towniand of Commons. The land, which is predominantly marshy, is of significant interest because it contains a rich variety of plant and wild-bird species. Local people had traditional rights to graze their livestock and geese. The Paramadda river, which rises in Thomastown bog, passes through the village and through the North Commons to join the River Nanny at Duleek Bridge just south of the village.

Collier the Robber, an alleged highwayman who attained notoriety during the early 19th century, is associated with the Commons. He was a Robin Hood-type character who was born in Bellewstown in 1780 and used the Commons on occasion as a hideout. Folklore has it that he attended a wedding in the area while a substantial sum was on his head. His first steps in crime were when he helped a young woman free her father and three brothers who had been arrested for horse-thieving. From here he progressed to mail coach robberies. He escaped hanging by being transported to Australia. Much folklore has built up around Collier.