How about a handmade, personalized Aztec calendar? You can find artisans on websites like Etsy who create custom Aztec calendars based on the specific date (or dates) that are significant to you both, such as your wedding anniversary or other important dates in your relationship. This would not only celebrate his interest in Aztec culture but would also make for a unique and meaningful anniversary gift. Additionally, you could pair it with a book about Aztec culture, or even plan a trip to visit historical Aztec sites.
Or you can get him a star map with the date of your anniversary.
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.