Lying about 14 miles north of Larne, this glen takes its name from the stone ditches in the upper glen and on Garron mountain. Some of these have been shown to date from the Bronze Age.
The main village is Carnlough (population about 1000) stretching along most of the bay. A further 500-600 people live in the upper glen. Archaeological excavations at Bay Farm have uncovered evidence of Neolithic occupation (around 4000 B.C.) and further excavations in the same general area uncovered a Bronze Age settlement dated between 2000 and 1500 B.C.
Doonan Fort about 2 miles west of Carnlough and Dungallan Fort about 2 miles north of Carnlough are Norman mottes. The great fort of Dunmaul at Garron Point was also adapted as a motte although it undoubtedly pre-dates the Normans. There is a strong local tradition that it was a Viking stronghold.
A survey of Glencloy identified four clachans – Gortnagory (1), Aghalum (2) Unshinagh (3) and Straidkilly (4) in the townland of Bay.