The Larnian is so called from the extensive deposits of flint implements found at Curreen Point which is situated in the harbour at Larne in Ulster.

Remains of a flint industry were found on the old shoreline on the coasts of Antrim and Down where the coast of Ireland faces that of Scotland.

This is the point where the shortest sea crossings can be made between the two countries.
The flint deposits have been found as far south as Dublin as north-west as Donegal.
These flint deposits tend to be found in the storm beache deposits of the old shoreline, because of this they are much battered and sometimes it's difficult to distinguish between artefacts of flint and natural flint.
The north-east of this area has the best fresh flint available in Ireland.
The raised beach in which the Larnian flints are found date to after the last ice age.