Photograph of Pacific Portland Cement Company's Plaster City Plant, showing cinder blocks in foreground, ca.1940. At center, a large pile of neatly stacked cinder blocks can be seen. Similar piles of cinder blocks are visible to the left extending into the background. Also in the foreground, long lines of cinder blocks stacked both vertically and horizontally can be seen. Each cinder block is a simple rectangular slab with three square openings at its center. In the background at center, a large pile of grinded stone or dirt can be seen. To the right, a group of utility poles and power units are visible. Further to the right, a series of wooden poles and beams support an elevated railway. A single railcar is seen atop the tracks. Further in the background at center, a group of large buildings are visible. Pipes and machinery extend from the building on the left, while windows and a large entryway can be seen on the group of buildings on the right. A single railroad track runs between these two groups of buildings, and a single car is visible between the two groups.