Fieldwork carried out by the Ordnance Survey in the nineteenth century indicates that there were several prehistoric monuments on or near Carrickgollogan. Little evidence of them remains today. A structure of three stones in a trilithon arrangement lies in a field to the south of the summit and it is uncertain as to whether this is the remains of a wedge tomb or a portal tomb. On the east side of the mountain a wedge tomb with a long gallery was discovered during the laying of a gas pipeline. It has since been reburied.