Everyone planning to visit Mexico must obtain a tarjeta de turista (tourist card). If you're flying to Mexico, the stewards on your plane will hand out tourist cards and customs-and-immigration forms on the plane before you land. If you're driving into Mexico, you can obtain one at the border or at any AAA office in the border states — California, Arizona, New Mexico, and Texas. Tourist cards are free and valid for ninety days. When you arrive in Mexico, the immigration officer who validates the card will ask you your destination in Mexico and how long you plan to stay, then he or she will tear off a portion and give that back to you. You should carry that portion with you at all times. It's a good idea to keep it inside your passport. If you lose your tourist card, it's a hassle to get another, and you may have to pay a fine. When you leave Mexico, you must turn it in.