Diamond Bar

Diamond Bar is a city in eastern Los Angeles County, spreading across rolling hills at the meeting point of the Pomona and Orange freeways. The residential neighborhoods cover roughly 14.9 square miles (38.5 square kilometers) and are dotted with parks, community centers, and shopping areas.

The area once formed the Rancho Los Nogales, granted by Governor Juan Alvarado to José de la Luz Linares in 1840. The 4,340-acre ranch later developed into residential neighborhoods, and the city was officially incorporated in 1989.

The name comes from a branding iron featuring a diamond shape above a horizontal bar, once used to mark cattle on the ranch. Today the city feels residential and suburban, with Asian markets, restaurants, and community centers shaping everyday routines.

The area sits at major freeway junctions and is best reached by car from Los Angeles or Orange County. The Diamond Bar Center offers event spaces and information for visitors who want to learn about local activities and facilities.

The community formed as one of the last incorporated cities in the greater Los Angeles area. Many residents commute daily to workplaces in surrounding counties and return in the evening to quieter residential streets.

Location: Los Angeles County

Inception: 1989

Shares border with: Walnut, Pomona, Rowland Heights, Chino Hills, Brea

Website: http://ci.diamond-bar.ca.us

GPS coordinates: 34.00167,-117.82083

Latest update: December 13, 2025 16:12