New historical plaque dedicated at Diego Sepulveda Adobe in Costa Mesa

County and city officials gathered in Costa Mesa’s Estancia Park on Saturday to unveil a plaque commemorating the history and significance of the Diego Sepulveda Adobe.

The event — presented by the Orange County Board of Supervisors and county Historical Commission in cooperation with the city — included a dedication ceremony and tours of the adobe at 1900 Adams Ave.

The adobe, which is maintained by the Costa Mesa Historical Society, was built as a station of Mission San Juan Capistrano roughly 200 years ago and is believed to be Costa Mesa’s oldest building.

It now houses a museum containing artifacts from and information about four periods of California history — Indian, Mission, Spanish and Victorian.

For more information, visit costamesahistory.org/visit/adobe.