From the San Diego Zoo:

Kid's Free Days
October 1 thru 31
The Zoological Society of San Diego was founded October 2, 1916. In honor of our special birthday month, children ages 3 to 11 receive complimentary admission to the San Diego Zoo, when accompanied by an adult, during the month of October! Check out some of the Zoo's youngsters, including cheetah and tiger cubs, young pygmy chimps, and our 2-year-old giant panda. And be sure to visit the Zoo's Children's Zoo with its touchable animals and colorful gardens.

Visit http://www.sandiegozoo.org/zoo/index.html for more info!!!