A view inside St. Leonard's Church in Hythe, England, dating from the 11th century.  The church is only one of two in England to contain a surviving ossuary, claiming "the largest and best-preserved collection of ancient human skulls and bones in Britain".  The chancel, dating from 1220, covers a processional ossuary (a bone store, more commonly found on the continent) lined with 2,000 skulls and 8,000 thigh bones. They date from the mediaeval period, probably having been stored after removal, to make way for new graves. This was common in England, but bones were usually dispersed, and this is thus a rare collection. Several of the skulls show marks of trepanning.

More info here: https://en.wikipedia.org/wiki/St_Leonard%27s_Church,_Hythe