A medieval grave slab stands south of St Bartholomew’s Church in Lostwithiel. This tapered, rectangular granite block measures about 1.26 metres high, 0.45 metres wide at the top (narrowing to 0.32 metres), and 0.17 metres thick. It is set upright in a modern granite base with its principal faces oriented north-south. The north face is plain, while the south face has unusual relief decoration: a circle with three small circular bosses at the top and bottom, an additional boss above the circle, and a long limb extending down from its base. There is also a deep cupped depression at the top, similar to a mortar, which makes this design quite distinctive compared to more conventional medieval grave slabs. The slab was discovered in the churchyard in 1850. Between 1857 and 1869, it served as a gravestone in the new cemetery before being brought back to the churchyard. It lay there until 1958 when it was finally set into its current granite base, which bears an inscription from the Lostwithiel Old Cornwall Society noting where it was found. Although two small drill holes are modern additions, likely made for attaching a memorial tablet during its time as a gravestone, the slab itself is believed to have been the lid of a medieval grave belonging to a wealthy or important person, possibly a priest.