There is a plaque by one of them. Thirty-one Moonlight Towers installed in Austin in 1895, each one illuminating 3000 square feet. Seventeen of them still remain and are still working.
San Diego had one in 1886.
They were carbon arc street lamps.
The Moonlight Towers were installed in response to a string of serial murders in Austin from 1884-1885.
In 1976, the 17 remaining towers were placed on the NRHP. There are clusters of them in downtown and residential areas.
Most photos of these are taken during the day, but can't convey a true sense of what they look like.