Carrickfergus, United Kingdom
1177
Portballintrae, United Kingdom
13th century
Enniskillen, United Kingdom
1428
Strangford, United Kingdom
15th century
Dunseverick, United Kingdom
6th century AD
Dundrum, United Kingdom
13th century
Killyleagh, United Kingdom
1180
Randalstown, United Kingdom
1345
Downpatrick, United Kingdom
15th century
Newtownards, United Kingdom
12th century
Newtownstewart, United Kingdom
14th century
Clough, United Kingdom
12th century
Ardglass, United Kingdom
15th century
Ardglass, United Kingdom
15th century
Ardglass, United Kingdom
15th century
Kilkeel, United Kingdom
13th century
Strangford, United Kingdom
1412-1441
Cushendun, United Kingdom
14th century
Portaferry, United Kingdom
1184
Downpatrick, United Kingdom
11th century
Ehrenbreitstein Fortress was built as the backbone of the regional fortification system, Festung Koblenz, by Prussia between 1817 and 1832 and guarded the middle Rhine region, an area that had been invaded by French troops repeatedly before. The fortress was never attacked.
Early fortifications at the site can be dated back to about 1000 BC. At about AD 1000 Ehrenbert erected a castle. The Archbishops of Trier expanded it with a supporting castle Burg Helferstein and guarded the Holy Tunic in it from 1657 to 1794. Successive Archbishops used the castle's strategic importance to barter between contending powers; thus in 1672 at the outset of war between France and Germany the Archbishop refused requests both from the envoys of Louis XIV and from Brandenburg's Ambassador, Christoph Caspar von Blumenthal, to permit the passage of troops across the Rhine.