This is the cache set by the Muskarana, from the newly released book "The Legend of the Muskarana", by Rivca Crsan (and published on Amazon.com). The cache is a black and clear tupperware filled with toys, trinkets, and gifts the Muskarana gave Tree over the years. Fun for the whole family in a family friendly location.
Gur Zhfxnenan vf jngpuvat... ohg qba'g tb qbja vagb gur cvg.