Forestiere Underground Gardens in Fresno is one of the Golden State's most unique attractions. Published on April 18, 2026 Fruit growing on the Cellar Tree. Credit: Robert Devoe-Peterson/Forestiere Underground Gardens Forestiere Underground Gardens in Fresno, California, were hand-carved over 40 years by one man using simple tools such as picks and shovels. The 10-acre site includes rooms, tunnels, and grottos where citrus trees and grapevines grow underground. Now a National Historic Site, the gardens are open for guided tours from March to December. Just outside the heart of Fresno, California, off Highway 99, travelers can find an unexpected gem: a subterranean garden blooming with citrus trees, flowers, and branches heavy with fruit. It's a marvel that defies every preconception that visitors may have about California's Central Valley. Forestiere Underground Gardens is a 10-acre subterranean complex with grottos, patios, and garden courts.…