How about a book on the Aztec Civilization or a personalized Aztec designed T-shirt? A beautiful Aztec jewelry piece like a pendant or a bracelet could also be a great option. You could also give him an Aztec print coffee mug or a set of coasters. If your grandpa likes to cook, get him an Aztec-style molcajete, which is a traditional Mexican pestle and mortar made from volcanic rock, or a recipe book of Aztec traditional cuisine.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.