Fullerton Arboretum | Cal State Fullerton - Fullerton Arboretum | CSUF, Come take a break from bustling city life and relax at our 26-acre botanical garden! The Fullerton Arboretum takes you on an adventure through trails, ponds and bridges to explore nature. This urban oasis is home to a variety of colorful plants and animals. There are flowers to smell, exotic trees to admire and even a bamboo xylophone! Enjoy a picnic by the waterfalls with the turtles and ducks, watch the birds and butterflies flutter around, or rest in the shade under our beautiful fruit trees.