According to Wikipedia: "Los Angeles City Hall, completed 1928, is the center of the government of the city of Los Angeles, California, and houses the mayor's office and the meeting chambers and offices of the Los Angeles City Council. It is located in the Civic Center district of downtown Los Angeles in the city block bounded by Main, Temple, First, and Spring streets."
This photo was sent in by MrK who notes that these fixtures are located just below the observation floor in the City Hall building.