These photos have been passed around several times over the years but become relevant again as we embark on construction of the Westside Subway Extension. This 1-mile subway line was built in 1925 from the downtown LA Subway Terminal Building at 4th and Hill, where you could board a trolley and travel underground-- beneath LA's increasingly congested streets -- to 2nd Street at Beverly and Glendale. It was shut down in 1955 due to the lack of interest in transit, and  the foundations for the Bonaventure Hotel filled up part of the line in the 1970s. Then even the mouth of the tunnel at Beverly and Glendale was obscuredin 2008 by construction of the Belmont Station Apartments.
http://www.gelatobaby.com/2012/05/11/las-original-subway/