What to do with old diaries/journals?

I kept a diary/journal from age 10 to my mid 20's and have 2 paper boxes full of them. My question is I am no longer interested in keeping them around. They contain a lot of private musings, some of which cover particularly hard times in my life that I have no desire to revisit. So what do I do with them? I feel like I don't want to throw them in the trash where they could be re-read. Do I burn them? Find a shredding company for them to be shredded? Thanks everyone! :-) 

[Moderator] Here is a similar question from the archives: https://www.berkeleyparentsnetwork.org/recommend/throwing-out-old-papers