A Vintage Photos Theme Park photo for the theme of X marks the spot (an X to indicate something or someone on the photo).

"C.M.T.C. Camp" is the label that appears below the main tent area in this photo, which is credited in the lower right-hand corner to the "Chicago Aerial Survey Co." This is a real photo postcard, and the type of Azo stamp box (with squares in all four corners) printed on the other side suggests that the card dates between 1924 and 1949.

Over 400 tents are visible in the photo, and the message that's part of the image says: "Had a fine trip here, all O.K. Here is my home for a month. X marks my tent. Everything looks fine so I'm sure I will like it here. Will write a letter soon." The postcard is unused, however, and no one has added an X to indicate a tent.

This C.M.T.C. Camp was located in Illinois at Fort Sheridan (now closed except for the Sheridan Reserve Center) and was one of about fifty Citizens' Military Training Camps, which were month-long training programs held each summer from 1921 to 1940 at U.S. Army posts.