AKA: Infomart Los Angeles, Downtown, Los Angeles, CA

Structure Type: built works - public buildings - post offices

Designers: Sarver and Zoss, Building Contractors (firm); Underwood, Gilbert Stanley, Architect (firm); Sarver (building contractor); Gilbert Stanley Underwood (architect); Zoss (building contractor)

Dates: constructed 1939-1940

3 stories, total floor area: 479,000 sq. ft.

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900 North Alameda Street
Downtown, Los Angeles, CA 90012

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Working as Consulting Architect for the US Treasury Department just before World War II, Gilbert Stanley Underwood designed this large mail-sorting building for the US Post Office. The facility received loads of mail via trains arriving at the nearby Union Station and served as the primary organizational nexus for the US Post Office in Los Angeles from 1938 until 1989. Underwood designed the building as a synthesis of the WPA Moderne and Spanish Colonial Revival Styles.

Building History

The Terminal Annex cost approximately $3 million to build, providing employment for many out-of-work builders and contractors during the mid-1930s. When it was completed, 1,632 postal employees worked in the cavernous post office sorting 2 million pieces of mail entering and leaving Los Angeles, CA daily. This number rose to nearly 2,000 workers by 1950.


NeXcomm Capital Partners of a limited partnership based in Southport, CT, leased the former Terminal Annex Post Office in 2000. This firm hired Johnson Fain Partners to redesign the space "...to attract high-tech and telecommunications tenants." (See Jesus Sanchez, Los Angeles Times.com, "Johnson Fain Is Infomart-L.A. Designer," published 10/10/2000, accessed 07/03/2018.) Thereafter, another firm, known as CoreSite, operated much of the building as a Tier 4 data center. This was known as its "LA2" data center in 2018 and contained over 424,000 square feet of space. According to the firm's web site, the Terminal Annex data center accomodated "scalable data center deployments including cabinets, partial cabs, cages, private suites, build-to-suit options and rooftop space." (See CoreSite.com, "Los Angeles Data Center," accessed 07/03/2018.)

National Register of Historic Places: 85000131 NRHP Images (pdf) NHRP Registration Form (pdf)

PCAD id: 22162