These are Peruvian handcrafted recreations of the ancient Ica stones.
The Ica Stones are a collection of andesite stones alleged to contain ancient depictions of dinosaurs and advanced technology. They were reportedly discovered in a cave near Ica, Peru not far from the Nazca Lines.
The Ica stones were popularized by Javier Cabrera, a Peruvian doctor who received an engraved stone as a birthday gift in 1961. Cabrera identified the engraving on the stone as a stylized depiction of an "extinct fish" that lived millions of years before.