Guards in the Doorway
I would say that I saw the most armed law enforcement (I think most were law enforcement) personnel in Mexico. Sub-machine gun toting officers was the norm. If you were messing about, you had better not be getting any of their attention.
Walking around the historic district of Merida, we investigated a museum like buidling that held artwork representing different stages of the Maya empire, from their rise to greatness to their eventual demise. This building actually became the scene for one of my first HDR photographs, a beautiful green terraced courtyard. These guards were taking a break at the front doors.