The sanctuary of the Sepulveda Unitarian Universalist Society is one of the most distinctive ecclesiastical buildings in all of Southern California.

It is nicknamed “The Onion,” and with good reason: with its round plan, bulbous shape, and near-total lack of windows, it looks like a giant space-age onion.

Its Unitarian Universalist congregation, established in 1943, found itself in the early 1960s in need of a larger space. Its members bought a five-acre ranch property in the North Hills area and began auditioning architects, hearing from luminaries like Richard Neutra.

The one who captured their imagination was Frank Ehrenthal, a former student of Neutra’s and a Universalist himself. In creating his design, Ehrenthal spent time talking with and observing members of the congregation to come up with a Modern design that would meet their needs. He presented a round building where people could face each other on equal footing.

Completed in 1964, “The Onion” is a dome-shaped building built of glue-laminated timber beams that curve all the way from the foundation to the flat point at the top of the roof. The entire building is clad with composition shingles (which originally were wood shake, no longer permitted by fire codes). It sits in the center of a large green lawn with trees and low shrubs.

Much beloved by its occupants, the church has been the site of numerous progressive lectures, protests, and even a Grateful Dead-Merry Prankster “Acid Test.” Conservancy Student Advocates from Kennedy High School’s Architectural and Digital Arts magnet program successfully nominated “The Onion” as a Los Angeles Historic-Cultural Monument in 2009.