The Kilkeel transmitter mast is Crown Castle owned and is situated on the summit of Aughrim Hill near Kilkeel.  The battle of Aughrim was fought there around 1690 ish, there's a spot of history for you.  There are no less than four towers on the hill, three on top, one of which is owned by Vodafone, and one just of the access road at the bottom which is owned by Orange.  The height of the television transmitting aerial is 304 meters aod.

The tv relay is confusing because the trough (receiving) aerial is directed over Carlingford Lough direction, I don't know where it's getting a feed from. Kilkeel has no direct line of sight with Divis (the main parent transmitter) due to the mountains. The large mountain in the pictures is Slieve Binnian.  The final picture is a long shot in more ways than one but if you look towards the centre of the picture you can see the Benagh Transmitter and Carlingford Lough behind.

Warren Wilding very kindly e-mailed us to explain:

The RX feed for this is recieved from a site at Killowen Mountain, NGR J207174, which is a purpose built active reflector (output channels, the same as the input channels) to give a reliable feed to Kilkeel.
 
Also as a point of further interest, the Kilkeel site is a proposed relay site for the forthcoming License for the FM station for the Newry and Mourne area which will be either Quay 100 or 5FM (licence decision process ongoing)