Tucked on the northern corner of the Cal State Fullerton campus, the Fullerton Arboretum is a 26-acre botanical garden that feels nothing like suburban Orange County. The grounds are organised into themed sections — a desert garden, a tropical rainforest collection, a California native plants area, a citrus and stone-fruit grove — with winding paths and ponds connecting them. The collection runs to more than 4,000 plant species.
The arboretum is owned by the university and free to enter (a small donation is requested). The 1894 Heritage House, a Victorian farmhouse moved here in 1972, sits in one corner and is open for tours on weekends. Closed Wednesdays. Allow at least an hour; the citrus collection in winter and the spring wildflowers are particular highlights.