The museum grew from the collection of Harvey Spencer Lewis, founder of the Rosicrucian order AMORC, which made San Jose its headquarters. The collection was first shown to the public in 1928, and new buildings in ancient Egyptian style opened in November 1966, set in a park of lawns, statues and fountains that fills nearly a city block.
Its holdings include a child mummy that was CT-scanned at Stanford in 2005. The park also has a planetarium, described as the fifth opened in the United States. In 2017 the museum reported about 110,000 visitors a year, among them some 26,000 sixth-graders.