Post a mapped photo whose 
at least one of the coordinates (latitude and longitude) are 
between -3 and +3 degrees compared to the previous posted photo. 
The numbers of latitude and longitude can be interchanged.
We consider only the first number, that of degrees: for example, 38° (N or S, E or W, no matter...).
The coordinates are below the map of your photos. 
I start, let’s see what happens…
Temple of Antoninus and Faustina (Rome), 41° N, 12° E.
(The next post may have at least one of the two coordinates between 38° and 44° or between 9° and 15°).