The earliest features of the castle are two large drum towers about 9 metres (30 ft) in diameter on the eastern side, both relics of a stronghold built here by the McQuillans after they became lords of the Route.

Sorley Boy swore allegiance to Queen Elizabeth I and his son Randal was made 1st Earl of Antrim by King James I.

A local legend states that at one point, part of the kitchen next to the cliff face collapsed into the sea, after which the wife of the owner refused to live in the castle any longer.

Randal McDonnell, Earl of Antrim, and his wife Katherine Villiers, Duchess of Buckingham bought lavish furnishings.

In 2011, major archaeological excavations found significant remains of the "lost town of Dunluce", which was razed to the ground in the Irish uprising of 1641.

[5] Lying adjacent to Dunluce Castle, the town was built around 1608 by Randall MacDonnell, the first Earl of Antrim, and pre-dates the official Plantation of Ulster.

It is a monument in state care sited in the townland of Dunluce, in Coleraine Borough Council area, at grid ref: C9048 4137.