The Windsor Square Hancock Park Historical Society is located in the Hancock Park neighborhood of Los Angeles, California—not in a separate municipality.
Hancock Park is an affluent, historic residential district in the Wilshire area of Central Los Angeles, bounded roughly by:
The Windsor Square-Hancock Park Historical Society serves both the Windsor Square (north of Wilshire) and Hancock Park neighborhoods. It preserves archives, advocates for historic preservation (HPOZ—Historic Preservation Overlay Zone), hosts tours/lectures, and maintains the area's architectural history. Their activities are centered in the neighborhood; they don't operate a separate public museum facility.
Hancock Park is a residential neighborhood—no admission, no gate. Walk the streets (Rossmore, Hudson, Oakwood, Lorraine, etc.) to admire architecture. The society's events are typically at local venues (Ebell Club, John Burroughs Middle School, private homes). Check their website for current programming.