SUNNYVALE — A major investment firm owned by a German financial services colossus has bought a big industrial building in Sunnyvale that is close to multiple mystery buildings where Apple operates.

RREEF, a unit of Germany-based Deutsche Bank, used an affiliate to purchase a large warehouse at 111 Uranium Dr. in Sunnyvale, Santa Clara County public documents filed on Dec. 13. show.

The warehouse, perched alongside nearby Caltrain tracks, totals 127,000 square feet, according to commercial real estate firm JLL, which arranged the transaction.

The RREEF affiliate paid $46.2 million on cash for the industrial building, the county property documents show.

The seller was Iron Mountain Information Management, an information storage and management company with $3 billion in yearly revenue. From protection and security for digital records to shredding paper documents, Iron Mountain boasts 95 percent of the Fortune 1000 as its customers.

As part of the property purchase by RREEF, Iron Mountain obtained a lease that will enable the company to remain as a tenant for “no more than three years” in a time period that began on Dec. 10, the county property files show.

The 111 Uranium Dr. location is of interest because it’s just down the street from some other industrial buildings where Apple operates in a secrecy-shrouded location at 127 through 137 Uranium Dr.

Separately, Apple has leased another two other old industrial buildings, one located at 3000 through 3008 Kifer Road, and the other at 2855 through 2865 Uranium Drive, totals 30,000 square feet.

Cupertino-based Apple has confirmed all of these leases on and near Uranium Drive but hasn’t discussed the nature of the operations inside the structures.

It wasn’t immediately clear whether RREEF intends to eventually redevelop the Sunnyvale building as a modern structure, or focus primarily on keeping the building leased once Iron Mountain departs.

“The warehouse building is centrally located in an infill Silicon Valley location within walking distance to the Lawrence Caltrain Station,” JLL noted in a prepared release.

The industrial building is one of the last remaining warehouses in Sunnyvale, said JLL brokers Ryan Sitov, Mark Detmer, Bo Mills, Greg Matter, and Tatiana Hodapp, who advised both Iron Mountain and RREEF on the transaction.

“There has not been any new warehouse construction in Sunnyvale since 1997,” the JLL agents said.