There may be an existing thread for night photography in the "Themes" Gallery. Have you checked there?
We try to limit the number of Gallery topics for quicker viewing, as well as for easier decision-making as to where to place your image.
In the instance of night photography, if you'd rather not use "Themes" you may want to place it according to the subject matter of the shot first. You can mention the fact that it's a night shot in your thread title.