The Diego Sepulveda Adobe encompasses nearly 200 years of Costa Mesa history in beautiful Estancia Park, overlooking the Santa Ana River bed. It is located at 1900 Adams Avenue. The Adobe is open the 1st and 3rd Saturday of each month 12pm – 4pm.
Diego Sepulveda Adobe

A colorful segment of Southern California history is preserved by this small adobe and its surrounding site. The story of the Diego Sepulveda Adobe (also known as the Estancia) dates back to an uncertain past. Only recently, in 1962, the skeleton of a mastodon was uncovered here. And the surrounding tableland has been recognized as a rich field for archaeological exploration.

History of the Adobe

Long before the first Spaniards came to California, native American Indians had settled on this mesa. Artifacts found here and in nearby Fairview Park suggest this site is part of the historically important village complex of Genga. Artifacts from this Indian period are exhibited in the adobe.

Six Spanish leagues southeast lies Mission San Juan Capistrano, founded in 1776. Fr. Zephyrin Englehardt, in his Missions of San Juan Capistrano, describes the adobe as a station of the Mission situated on the banks of the Santa Ana River.

At first, the site was an Indian settlement, occasionally visited by the Padres. In the early 1800s, when the Capistrano cattle (made famous by Richard Henry Dana in his Two Years Before the Mast) grazed in what is now Costa Mesa, provision had to be made to shelter the herdsmen. Possibly as early as 1817, but more likely between 1820 and 1823, a small adobe was built to house the majordomo and his men. The large “mission” bricks of this first structure were found in the east and south walls.

As the Mission Period passed, the old Spanish land grants were partitioned and the adobe became the property of Don Diego Sepulveda, a former alcalde of the Pueblo de Los Angeles. It assumed its present shape during the Sepulveda tenancy. The additions he made are indicated in the walls by the change to smaller, ranch-type adobe bricks.

There were neighbors then – the Eduardo Pollereno adobe to the south and another adobe to the north – each in a prime location on the mesa with its own well of fresh water. As late as 1868 these were the only homes in the area. The structure appears as the “House of Diego Sepulveda” on a map of that year that now hangs in the east room.

Then came a period of transition – the passing of the era of the Dons – and the adobe became a part of a larger, rambling ranch house. From the outside, the adobe walls were all but hidden except for the east wall, and even that was plastered over. A frame structure was built to the west and the entire combined building was housed under a high peaked roof to which we owe the preservation of the old adobe walls.

Gabe Allen, a colorful Los Angeles character who had fought in the Mexican war, next acquired the property. Subsequently, his brother, Jesse Allen, occupied the house for seventeen years. Some of the lumber used in building the ranch house came from the Civil War Drum Barracks in Wilmington, California. Unless a passerby looked closely, the fact that a portion of the building was adobe would not have been noticed. From the Allens, the adobe passed to the Adams family, for whom Adams Ave is named. On a 1939 map the building appears as the “Derby Ranch”.

After the first World War, Costa Mesa Post 455, American Legion, held its first meetings at the adobe. The original flagpole erected by the post now stands on the grounds of Harbor Rest Cemetery (now Harbor Lawn – Mount Olive).

In 1940 the property was purchased by the Segerstrom family and in 1963 the Adobe and the surrounding 5-acre site were given to the City of Costa Mesa by members of the Segerstrom family as a memorial to the early settlers of the area.

The frame structure concealing the Adobe was removed and the adobe was restored. A special committee of the Costa Mesa Chamber of Commerce assumed the task of establishing a museum inside the building. In 1966, the special committee became the nucleus of the Costa Mesa Historical Society. Today the adobe represents an important element in preserving the history of Southern California.

The Interior

Four distinct periods of California history are represented in the rooms of the adobe – Indian, Mission, Spanish, and Victorian. The Costa Mesa Historical Society has used these periods as guidelines for furnishing the adobe.

Southwest Room (Kitchen)

This earliest room is entered through a low doorway from the main room. The floor of packed earth has been left as it was when the first bricks were laid. Originally, the roof over this room was made of tiles and tar, large sections of which were found when the ranchhouse superstructure was removed. The room is restored as a kitchen of the mission/rancho era.

East Room (Main Room)

The largest of the adobe’s rooms has been devoted to the Spanish-Californian heritage, when it was at its functional peak under the ownership of Don Diego Sepulveda. This room serves as a reception area for visitors and also contains several exhibit cases. On the walls are an 1868 map of the area donated by Title Insurance & Trust Company and the Chain of Title to the property, donated by North American Title Insurance Company.

Northwest Room (Bedroom)

Here the Victorian period is captured by furnishing the room as it might have been during the years it was known as the Allen Adobe. This marks the final period of the building before it became a little-used portion of the larger wood-framed ranch house described above.

Activities and Events

The Diego Sepulveda Adobe is open the 1st and 3rd Saturday of each month 12pm – 4pm. The Society hosts an annual open house for the community, usually in mid-September. Watch our Public Events page for information on upcoming events. The grounds of Estancia Park may be scheduled to host your reception, wedding, or other private function. Please contact the Costa Mesa Recreation Department at 714-754-5300 to schedule your private event.


If you’re interested in volunteering to staff the Diego Sepulveda Adobe, please fill out our Volunteer form and indicate your special interests.