Known. An early Christian church lay under a former fish market.
The church is in Oderzo, the ancient town of Opitergium, in Italy. It dates to the 4th and 5th centuries AD. It had stayed hidden for 1,600 years. It is a large rectangle of brick and mortar, with a hall of three aisles. The south aisle has a coloured mosaic of shapes and flowers. One panel has an eight-sided centre and a Solomon's knot. Four graves lie outside the south wall, between the buttresses. The dead were wrapped in simple cloth, with no coffin and no grave gifts. Three of the graves held two people each.
The page says radiocarbon tests are still needed to date the church more exactly.