The Diego Sepulveda Adobe, also known as the Estancia, sits on a bluff overlooking the Santa Ana River bed in Estancia Park. The Segerstrom family purchased the property surrounding the Adobe in 1940. The Segerstrom family recognized the Adobe as an important part of history and donated the land, and the Estancia, to the City of Costa Mesa in 1963. The land and structure was donated to serve as a memorial to the early settlers of the area. The Adobe is the second oldest structure in Orange County and is California Historical Landmark number 227.
Shortly after the Abode was donated, a frame covering the structure was removed, revealing the original structure. The Adobe was then restored. A committee of the Costa Mesa Chamber of Commerce established the museum inside of the building. In 1966, the committee became the Costa Mesa Historical Society, which have been the caretakers of the building ever since. The interior museum represents four distinct periods in Orange County history - Indian, Mission, Spanish and Victorian.
Although the current incarnation of the Adobe is a museum, it was originally built between 1817 and 1823 to house the herdsmen who tended the cattle and horses from Mission San Juan Capistrano. The Estancia is located six Spanish Leagues, or about 24 miles, north of the mission.
From its founding in the early 1800s to its purchase from the Segerstrom family in 1940, the Adobe changed ownership several times. As the Mission Period passed, Spanish land grants were partitioned and the Adobe became property of Don Diego Sepulveda. Next, Gabe Allen, a Los Angelino who fought in the Mexican-American War, acquired it. Allen's brother occupied the house for the next 16 years. The Allen family passed the Adobe on to the Adams family. The Adobe then served as a meeting post for the American Legion after the First World War.
The Estancia can schedule to host an event by contacting the Costa Mesa Recreation Department at 714.754.5300.