'Complete mystery:' Roman slab found in a garden in England

An ancient Roman marble slab, used for nearly a decade as a horse mounting block before its origins were revealed, is at the center of a mystery as experts scramble to find out how it ended up in the garden of a bungalow in England.

source https://www.cnn.com/style/article/roman-slab-mystery-gbr-scli-intl-scn/index.html