| turbot |
1 |
| Turkey |
46 |
| Turkic (Mongol) tribes |
4 |
| Turkic mythology |
1 |
| Turkish bath |
4 |
| Turkish cemetery |
2 |
| Turkish Straits |
1 |
| Turkish Stream gas transit pipeline |
2 |
| Turkish Stream natural gas pipeline |
2 |
| Turluka |
1 |
| Turno Magurele |
1 |
| Turnu Magurele |
1 |
| Tutrakan |
2 |
| Tutrakan Mayor |
1 |
| Tutrakan Municipality |
1 |
| TV set |
1 |
| Tvarditsa |
1 |
| Tvarditsa Municipality |
1 |
| Tvarditsa Museum of History |
1 |
| Tvarditsa Pass |
1 |
| two-humped camel |
1 |
| two-sloped roof |
1 |
| Tyche |
2 |
| tyet |
1 |
| Tyrrhenians |
1 |
| Tzvetana Popova |
1 |
| U5B1b haplogroup |
1 |
| UAE Ambassador |
1 |
| Ubayd Allah al-Mahdi Billah |
1 |
| Ugarchin |
1 |
| UK |
65 |
| UK Education Foundation |
6 |
| Ukraine |
23 |
| Ukrainian Orthodox Church from the Moscow Patriarchate |
1 |
| Ukrainians |
1 |
| Ulan Bator |
2 |
| Ulcindur |
1 |
| Uldin |
1 |
| Ulfilas (Wulfila) |
4 |
| Ulpia Oescus |
24 |
| Ulpia Oescus Archaeological Preserve |
11 |
| Ulpia Oescus Thermae |
1 |
| Uluburun Cape |
1 |
| Uluburun shipwreck |
1 |
| Umay |
1 |
| Umayyad Caliphate |
1 |
| umbo |
2 |
| umbo (shield boss) |
3 |
| UN |
1 |
| underfloor heating |
10 |
| underground museum of St. Sofia Basilica necropolis |
10 |
| underwater archaeology |
46 |
| underwater caves |
4 |
| underwater cultural heritage |
4 |
| underwater photogrammetry |
1 |
| underwater wedding |
2 |
| underworld |
4 |
| undesignated archaeological sites |
1 |
| UNESCO |
15 |
| UNESCO Convention on the Protection of the Underwater Cultural Heritage |
4 |
| UNESCO Convention on the Protocol of the Underwater Cultural Heritage |
2 |
| UNESCO World Heritage site |
13 |
| ungulate mammal |
2 |
| Unification Day |
9 |
| Union of Collectors in Bulgaria |
2 |
| United Arab Emirates |
2 |
| United Kingdom |
1 |
| United Nations' Intergovernmental Panel on Climate Change |
1 |
| United States |
1 |
| University Crisis of 1907 |
1 |
| University of Basel |
1 |
| University of Bonn |
1 |
| University of California San Diego |
1 |
| University of Cambridge |
3 |
| University of Clermont-Ferrand |
1 |
| University of Connecticut |
4 |
| University of Copenhagen |
5 |
| University of Edinburgh |
2 |
| University of Ferrara |
1 |
| University of Geneva |
1 |
| University of Glasgow |
3 |
| University of Helsinki |
1 |
| University of Library Studies and IT in Sofia |
2 |
| University of Lille |
3 |
| University of Liverpool |
2 |
| University of Nebraska-Lincoln |
1 |
| University of New Mexico |
1 |
| University of Oslo |
2 |
| University of Quebec at Rimouski |
2 |
| University of Siegen |
1 |
| University of Southampton |
4 |
| University of Sydney |
1 |
| University of the Witwatersrand |
1 |
| University of Tuebingen |
2 |
| University of Warsaw |
6 |
| university students |
2 |
| Upper Austria |
1 |
| Upper Paleolithic |
1 |
| Upper Thracian Plain |
3 |
| Upper Voden Fortress |
3 |
