The Oakland Zoo by MaxMaraMama
This is a great, small zoo that can be enjoyed in it's entirety in about half a day. There have been constant improvements made over the past several years (perhaps longer), most recently the excellent expansion of the Children's Zoo, where you'll find climbing structures, sheep and goats in the petting area that you can brush, as well as lemurs, enormous fruit bats, giant tortoises, alligators, bunnies, otters and more. In the main zoo highlights include giraffes, lions and tigers, elephants, and a fun meerkat display with a plexiglass-ended tunnel for kids that brings them right into their world.
Be prepared to walk some steep hills to get around and bring sunblock on a clear day. You can take the sky ride (not unlike a ski lift) above the park to see great views of the animals. Younger kids will also enjoy the amusement park with quaint rides, including a charming merry-go-round and a small-scale "steam" train that takes visitors for a short ride around the park and back.