Children two years old and younger receive free admission to Six Flags Fiesta Texas. A guest does not need a season pass until they turn three years old. Once your child is three years old, the price would be the same as the other passes. If your two-year old is going to turn three during the current season, then we recommend buying the pass now, as it is usually cheaper than it will be later in the season. A child must be under 48 inches tall and under the age of 12 to be eligible for a child’s tickets. If not then you must purchase an adult ticket.