Thank you Luis! Sent on March 8th, this stunning cover featuring a Teotihuacan s/s from 2010 only arrived today. 
Thank you Luis for the FDC format. 
Thank you Monica for this surprise cover! The 2010 joint issue s/s has Teotihuacan and the Azerbaijan site of Ateshgah of Baku on it.
Psychedelic lithograph? 
1970s postcard of the famous site!