The Nimrud Lens: a 2,700-year-old crystal artefact that may have been part of a telescope

The Nimrud Lens is a small object carved from rock crystal more than 2,700 years ago in ancient Assyria. It is considered one of the most enigmatic artefacts in the history of optics, with one hypothesis suggesting it may have formed part of a primitive telescope used by Assyrian astronomers. It was unearthed by British archaeologist Austen Henry Layard during 19th-century excavations at Nimrud.