Document destruction services

Hi, I have a box of confidential papers that I do not need. I would prefer not to just throw them away, but to either shred or incinerate them. Due to the sheer size of the box, it is not practical for me to buy and use a home shredder. Would anyone have a suggestion as to what is the best way to destroy them? Aer there any services that do it inexpensively? Thank you igor