Ballycastle

Market town and seaside resort in the north of County Antrim, Northern Ireland; population (2001) 5,100. It is the port from which Rathlin Island is reached. Ballycastle's large Lammas Fair has been held since 1606 on the last Monday and Tuesday in August; a feature of the fair is to eat dulse, a dried seaweed.

There are a number of medieval ruins around Ballycastle, including Bonamargy friary (1 km east), an 11-m/35-ft round tower (8 km/5 mi south near Armoy), and Dunaneanie Castle (1 km west). Knocklayd Mountain (517 m/1,695 ft) is to the south, as is Ballycastle Forest; the sheer columnar basalt cliffs of Fairhead (190 m/626 ft) are 10 km/6 mi to the east, and impressive basaltic columns are also found at Grace Staples Cave to the west of Ballycastle.

The Italian inventor Guglielmo Marconi made the first successful wireless transmissions over water from Ballycastle to Rathlin Island in 1898.