How about a Celtic knot puzzle or a Celtic knot book that explains the meaning behind each knot and how they've been used throughout history? Another option could be a custom-made piece of jewelry with a Celtic knot design, like a pendant or bracelet. You could also consider booking a guided tour of a local Celtic museum or exhibit together, or a trip to a Celtic festival in the area. Finally, you could also consider buying him a book or movie that features stories from Celtic mythology or history.
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.