County Down on Wikipedia.

Annahilt, Church of the Ascension, (Church of Ireland). © Jack Storey, Monaghan Genealogy Specialist.
Ardglass, Church of Ireland. © Jack Storey, Monaghan Genealogy Specialist.

Ballygowan, Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.
Ballykinlar, St. Patrick and St. Joseph (R.C.) at North Tyrella. © Len Brankin.
Ballyroney, the Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.
Banbridge, Magherally Presbyterian Church. Magherally Ruined Church. Both © Jack Storey, Monaghan Genealogy Specialist.

Carrowdore, Christ Church (CoI). Many members of the Crommellin family of Carrowdore Castle are buried here. © Jack Storey, Monaghan Genealogy Specialist.
Clough, Church of Ireland. © Jack Storey, Monaghan Genealogy Specialist.
Comber, 1st Comber Presbyterian Church. Comber 2nd Presbyterian Church. Both © Jack Storey, Monaghan Genealogy Specialist. Alla Church. From an old postcard in Reg Dosell's Collection.
Crossgar, Christ Church (Church of Ireland) at Kilmore. © Jack Storey, Monaghan Genealogy Specialist.

Donaghcloney, Methodist Church. © Jack Storey, Monaghan Genealogy Specialist. Presbyterian Church, from an old postcard in Reg Dosell's Collection.
Downpatrick.
Dromore.
Drumballyroney, Church of Ireland. Famous for its Bronte connections, several members of the family are buried here, and Charlotte and Emily's father preached here. © Jack Storey, Monaghan Genealogy Specialist.
Drumbeg, Church of Ireland. © Jack Storey, Monaghan Genealogy Specialist. An old postcard view, from Reg Dosell's Collection.
Drumbo, Ballylesson Trinity Church, (Church of Ireland). © Jack Storey, Monaghan Genealogy Specialist.
Dundrum, Sacred Heart (R.C.). © Len Brankin.

Hillsborough.
Holywood.

Katesbridge, Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.
Killinchy, Parish Church. © Jack Storey, Monaghan Genealogy Specialist.
Killyleagh, Presbyterian Church. Church of Ireland. First Killyleagh Presbyterian Church. All © Jack Storey, Monaghan Genealogy Specialist.

Lambeg, Church of Ireland. © Jack Storey, Monaghan Genealogy Specialist.
Lisburn. Lisburn straddles the border of Counties Down and Antrim - the county boundary being the River Lagan (see Wikipedia entry).
Listooder, the Kilmore Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.

Magheralin, Church of the Holy & Undivided Trinity (Church of Ireland). © Jack Storey, Monaghan Genealogy Specialist. St. Patrick (R.C.). © Len Brankin. Link. The Evangelist Memorial Hall. J 125 589. © Gerard Close.
Moira, Methodist Church. J 146 604. © Gerard Close.

Newry.

Rademon, Non-Subscribing Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.
Raffrey, Presbyterian Church. © Jack Storey, Monaghan Genealogy Specialist.

Saintfield, Church of Ireland. © Jack Storey, Monaghan Genealogy Specialist.
Saul, St. Patrick's Memorial Church (CoI). This sign tells its story. Both © Jack Storey, Monaghan Genealogy Specialist.