| MANHATTANPROJECT | Research undertaking that led to the first nuclear weapons |
| APOLLO | Project that led to the first moonwalk |
| ROYALCHARTER | Steam clipper wrecked in an 1859 storm which led to the first gale warning service being introduced by the Meteorological Office |
| ENTERPRISEZONE | Area around the first nuclear aircraft carrier? |
| ALAMOGORDO | Site of the first nuclear explosion |
| FERMI | Enrico ___ , Italian-American physicist, creator of the first nuclear reactor, d. 1954 (5) |
| BIGBANG | According to cosmological theories the event/explosion that led to the formation of the universe (3,4) |
| EDSA | The avenue in Manila (Philippines) which made concrete before the world the Filipinos' people power that led to the fall of Marcos from power |
| DUMBARTONOAKS | Historic estate in Washington, DC that was the scene of conferences in 1944 that led to the creation of the United Nations (9,4) |
| DUMBARTON | Estate in the District of Columbia, US, that hosted a 1944 conference that led to the formation of the United Nations (9) |
| OAKS | Estate in the District of Columbia, US, that hosted a 1944 conference that led to the formation of the United Nations (4) |
| ATOLL | Coral island and surrounding reef such as Diego Garcia (used by the US as a air base in the Indian Ocean) and Mururoa (used by the French to test nuclear weapons in the Pacific) |
| NINETY | 19__, year of the terrible aeroplane crash that led to the village of Beckindale changing its name to Emmerdale (6-5) |
| REVOLUTION | Series of events in 1917 that led to the formation of the USSR, the Russian ... |
| IRANIAN | ____ Revolution, popular uprising that led to the overthrow of the Shah in the late 1970s (7) |
| EMS | German town associated with the 1870 dispatch from Bismarck that led to the outbreak of the Franco-Prussian War |
| MAASTRICHT | Dutch city associated with a treaty that led to the creation of the European Union and the Euro |
| ASWANDAM | The engineering feat that led to the creation of Lake Nasser? (5,3) |
| GIJANE | Movie in the joke that led to the Will Smith/Chris Rock slap |
| IRAN | IRA takes on first nuclear country in the Middle East |
