Place
- Cargill, Perthshire2
- Carisbrook Castle, Isle of Wight2
- Carnac, Bretagne2
- Carnhedryn, Pembrokeshire2
- Cashel, Tipperary2
- Castle Dermot, Kildare2
- Caswilia al. Castle Villa, Pembrokeshire2
- Cefn Amwlch, Carnary2
- Checkley, Staffordshire2
- Chichester, England2
- Chiswick, Middlesex2
- Cirencester, England2
- Clatt, Aberdeenshire2
- Clogher, Tyrone2
- Closeburn, Dumfriesshire2
- Coldingham, Scotland2
- Conningsburgh, Shetland2
- Conway, Caernarfonshire2
- Conwil Caio, Carmarthenshire2
- Corfu, the Ionian Islands2