County Boundary Stone, 11 Magherabuoy Road, Ballywillian, Portrush, Co Antrim BT56 8NU

A small cast or stamped concrete boundary marker standing on the north side of Magherabuoy Road, approximately 2 kilometres south-east of Portrush. The marker measures approximately 300 by 600 by 150 millimetres, with an integral cast base approximately 100 to 150 millimetres wide all around, and is positioned in a grass verge between a field access and a private house access. A mature tree and hedgerow stand immediately behind.

The front face bears lettering approximately 25 to 35 millimetres high, cast or stamped into the concrete, reading "COUNTY BOUNDARY ANTRIM DERRY". The horizontal words "ANTRIM" and "DERRY" are interlaced with the vertical word "BOUNDARY" using the letters "A" and "Y". The marker is weathered and exhibits severe damage and surface loss to the upper right sections of both front and back faces. The lettering for "COUNTY" is severely weathered with the "Y" missing, and most upper letters are partly missing. The marker has tilted towards both north-east and south-east, exposing the integral cast base.

This boundary marker is one of six similar stones set along rural roadsides in the area north and west of Ballymoney and east and south of Coleraine, Portstewart and Portrush, all marking the land boundary between counties Antrim and Londonderry, particularly where the boundary changes direction. Their precise date is uncertain, though the concrete construction and inscription styling suggest they date from the very late 19th or early 20th century, possibly associated with the introduction of County Councils following the 1898 Local Government (Ireland) Act. By 1940, their origins appear to have been obscure; a photograph of a similar stone in nearby Glebe townland south of Portrush appeared in the Belfast Telegraph on 21 May 1940, captioned "A curious county boundary stone". This particular example first appears on Ordnance Survey maps of 1939 but does not feature on any later editions. Of the six known surviving examples, at least one other stone once stood along Newbridge Road north-west of Ballymoney but was removed around 2020. Despite their modest size and simple detailing, these unusual boundary markers hold special local and historical importance.