San Diego International Airport (SAN), still widely known by its old name Lindbergh Field, sits three miles northwest of downtown — one of the closest urban airports to a city centre in the US. It has direct flights from most major North American hubs and a growing roster of international routes (London, Tokyo, Frankfurt, Mexico City). The airport is small enough to clear quickly, and a short bus ride or taxi gets you downtown.
By car, I-5 runs the length of the California coast and connects San Diego to Los Angeles (about two hours without traffic) and on to San Francisco. I-15 heads northeast through the desert to Las Vegas (five hours) and Salt Lake City. I-8 crosses east into Arizona. Amtrak's Pacific Surfliner runs eleven daily trains up the coast to Los Angeles via Solana Beach, Oceanside and San Juan Capistrano — one of the more scenic short rail trips in the country.
The Mexican border at San Ysidro is twenty minutes south, easily reached by trolley. Bring your passport.