One idea could be to book a rock climbing trip or lesson for the two of you. Alternatively, you could get him a piece of new climbing gear. I would recommend a good quality chalk bag or climbing shoes, as those are always necessary and appreciated by climbers. Another idea could be to create a personalized rock climbing photo book highlighting all the great moments you have shared together while climbing.
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.