London, with its six international airports - Heathrow (LHR), Gatwick (LGW), Stansted (STN), Luton (LTN), London City (LCY), and Southend (SEN) - serves as one of the world's major aviation hubs. Heathrow, being the busiest, handles most long-haul international flights, while Gatwick offers a mix of international and European services. Stansted and Luton are popular with low-cost carriers serving European...