The longest continuously operating olive cannery in the United States, the Graber Olive House is a small compound of wooden curing-house buildings on a quiet residential street north of downtown Ontario. The free self-guided tour walks you past the original grading and packing machinery and explains the slow tree-ripened curing process. October and November, during harvest, is the most interesting time to visit.
There is a small museum room with photographs and old labels, a gift shop selling olives and olive oil, and a shaded picnic area under century-old olive trees. Address: 315 East Fourth Street. Free; open daily.