There is a 10 acre Botanic Garden in the Tilden Regional Park. There are ten sections to represent the ten different regions in California (including the California Rain Forest). They are laid out nicely with nice hiking trails throughout.
The kids really enjoyed the Botanic Garden as did my nephew Steve. Steve is a landscape architect and learned some new plants to use in the business.
There is also a small farm in Tilden Regional Park. It is very educational showing how farms work and many of the animals raised on farms. Kids love seeing the animals.
There is also a nursery building where they cultivate seedlings and a succulent building where they have various forms of cacti.
As you walk through the various sections of the garden you will see signs letting you know what section you are entering.