McMartin Preschool was a private preschool located in Manhattan Beach, California. It became widely known in the 1980s due to a highly publicized child abuse case that involved allegations of sexual abuse by staff members. The case led to a lengthy investigation and trial, which became one of the longest and most expensive in U.S. history. The allegations against McMartin Preschool sparked national media attention and raised concerns about child safety and the reliability of children's testimonies. Ultimately, the case resulted in no convictions, but it left a lasting impact on the community and influenced discussions about child protection laws and practices.