| Name | Country | 14C dates | |
|---|---|---|---|
|
301-320 / 460 show all | |||
| Oblast Ternopil | Ukraine | 0 | Show |
| Oblast Volyn | Ukraine | 1 | Show |
| Oblast Winnyzja | Ukraine | 5 | Show |
| Oblast Zakarpattia | Ukraine | 0 | Show |
| Obwalden | Switzerland | 0 | Show |
| Odense Amt | Denmark | 4 | Show |
| Oise | France | 0 | Show |
| Öland | Sweden | 94 | Show |
| Olmütz | Czech Republic | 3 | Show |
| Olt | Romania | 0 | Show |
| Oppeln | Poland | 42 | Show |
| Örebro | Sweden | 0 | Show |
| Orkney | United Kingdom | 31 | Show |
| Orkney Islands | United Kingdom | 0 | Show |
| Östergötland | Sweden | 14 | Show |
| Østfold | Norway | 19 | Show |
| Overijssel | Netherlands | 14 | Show |
| Oxfordshire | United Kingdom | 26 | Show |
| País Vasco | Spain | 0 | Show |
| Pas de Calais | France | 0 | Show |
