How about creating a personalized poetry book for your boyfriend? You could write your own poems and include some of his favorite poems from his favorite poetry slams. You could even include some of his own poems or ones he's performed at poetry slams. Another idea is to buy tickets to a poetry slam event and make a date out of it. This would show your support for his interests and give him an experience he will always remember.
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.