Cranfield Point is the southernmost point

Extreme points of the United Kingdom

This is a list of the extreme points of the United Kingdom: the points that are farther north, south, east or west than any other location. Traditionally the extent of the island of Great Britain has stretched "from Land's End to John o' Groats" .This article does not include references to the...

 of Northern Ireland

Northern Ireland

Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...

. It is located at the mouth of Carlingford Lough

Carlingford Lough

Carlingford Lough is a glacial fjord or sea inlet that forms part of the border between Northern Ireland to the north and the Republic of Ireland to the south. On its northern shore is County Down and on its southern shore is County Louth...

 in the townland

Townland

A townland or bally is a small geographical division of land used in Ireland. The townland system is of Gaelic origin—most townlands are believed to pre-date the Norman invasion and most have names derived from the Irish language...

 of Cranfield, County Down

County Down

-Cities:*Belfast *Newry -Large towns:*Dundonald*Newtownards*Bangor-Medium towns:...

.

It was once the site of the Cranfield Point lighthouse

Lighthouse

A lighthouse is a tower, building, or other type of structure designed to emit light from a system of lamps and lenses or, in older times, from a fire, and used as an aid to navigation for maritime pilots at sea or on inland waterways....

, marking the entrance to the lough. Its poor position led to the construction of the Haulbowline Lighthouse situated in the middle of the entrance to Carlingford Lough. Cranfield Point Lighthouse subsequently fell victim to coastal erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

and collapsed into the sea during the 1860s. The lighthouse keeper's cottage remained and was later converted into a private residence that can still be seen today, identified by its characteristic tall black chimneys.