A box where one keeps all their freaky sex toys, and accesories (such as S&M or bondage gear). Usually hid in a dark closet, attic or under one's bed.
I found Steve's treasure chest. It was full of anal beads, ribbed double sided dildos, handcuffs, 3 different whipes, ass-less chaps, a leash, and a gagball. Steve is one sick fuck.