The Zoo celebrates its 100th anniversary this year. The Zoo and Safari Park have become world famous not only for the animals but also the outstanding plant collections and gardens. So much so, the San Diego Horticultural Society has named the park their “Horticulturalist of the Year”. There will be special tours on this Saturday and experts available to answer questions. 9 a.m. to 1:00 p.m. When you register to attend, you can receive via email a discount voucher good for 20% off regular entrance fee.