23 West 13th Street, c. 1994 Substation 235, located at 23 West 13th Street on at the intersection of Greenwich Avenue and Horatio Street. The structure was built in 1932 during the construction of the IND Eighth Avenue Line, a project that lasted from 1932 until 1940. A substation is fed power from a central station that is converted from high voltage alternating current (AC) into low voltage direct current (DC) to power the subway. This substation and others constructed for the IND line were the first to be non-manually operated. Greenwich Substation was listed on the National Register of Historic Places in 2005 as a unique piece of New York City's transit history. The masonry structure's footprint, a chamfered rectangle, reflects the infill lot's geometric condition at this bustling intersection. The facade is adorned with limestone, brick, and aluminum; its loading dock doors are framed by Art Deco motifs and sunburst patterns, not uncommon of substations and telephone buildings of the era. The human-scaled entrance is decorated more modestly and located at the level of the sidewalk.