St. Louis has had many grand private streets where the homes of the rich were or are located. Some, in neighborhoods that became undesirable (mostly closer to the Mississippi) are gone. Many from the late 19th and early 20th Centuries, mostly west of Kingshighway, survive. One of the most opulent was Vandeventer Place. (Some history here.) Now the area is, well, not so great. The mansions were razed and the development destroyed.
All of these private streets had elaborate entrance gates. For some odd reason, the entrance to Vandeventer Place was preserved and plopped down in an open area of Forest Park in 1950. It's near the Jewel Box and the Korean War Memorial seen a couple of days ago. Now it is an entrance to nowhere.