An unusual collection of found-object art in Chichibu, Japan is home to nearly 2000 rocks that naturally feature what appear to be facial expressions.

A jinmenseki (or: rock with human face) can look like anything from an abstract emoji to a famous figure, including ones in this array that are purported to resemble Donkey Kong, Nemo and Elvis Presley.

The founder of the museum, Shozo Hayama, passed away after 50 years of collecting and left the space and its collection to his wife Hayama six years ago. The key criteria: nature is the only artist in the mix (no modified rocks allowed).

Some of the rocks are named while others simply set on the shelves, left open to interpretation. Visitors can simply show up but are advised to call ahead since the hours of opening are not entirely consistent or predictable (h/t Spoon & Tamago).