The Fairgrounds in San Antonio Xahuento and Throughout Tultepec|Terrenos de la Feria Nacional de la Pirotecnia Tultepec, Tultepec, Mexico | Map
Wrap it up
Though Tultepec is rarely cold in March, it's wise to wrap up in thick clothing made of cotton and denim. Also be sure to bring along a hoodie, cotton scarf and/or goggles so that you'll be able to see and breathe amidst the smoky fireworks.
Keep your wits about you
Consider skipping that second (or third) drink, and even the harder stuff. Especially on the perimeter of the wide-open fairgrounds, where attendees are free to run pell-mell through explosions of fireworks, it's a good idea to have a grip on your reflexes and a clear sense of how to get to safe ground.
Lock it up
Renting a car is certainly an option if you'll be staying near the festival, but be sure not to leave valuables in your vehicle; there are few events in Mexico that provide more distractions and better cover for thieves.