How about getting them a personalized replica of an archaeological artifact? You can do some research into artifacts from their favorite time period or culture, and have a replica made with their names or wedding date engraved onto it. Alternatively, you could get them a framed print or map of an archaeological site they've always wanted to visit, or a book on a particular archaeological discovery or method. Another option would be a gift certificate for an archaeological tour or event in their area.
Or you can get her/him a star map with the date of the wedding.
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.