Assertion: stone altar | /r/HasProperty | the tombs of martyrs
Facets:
value: on a stone slab
type: LOCATION
value: on a structure
type: LOCATION
Source sentences:
text: The earliest stone altars were the tombs of martyrs, over which Mass was sometimes offered, either on a stone slab enclosing the tomb or on a structure placed above it.
text: The earliest stone altars were the tombs of the martyrs interred in the Roman Catacombs.