36.1653°N, 1.3345°E.
Basilica of St. Reparatus Labyrinth is a labyrinth installation in Chlef (formerly Orleansville), Algeria. The design is a roman meander layout with 4 circuits, 5 walls, approximately 2.4 metres in diameter, built of mosaic. Documented age: 324 CE (324 CE). Current condition: damaged. The earliest known labyrinth in a Christian church, dating to 324 CE — the very year Constantine convened the Council of Nicaea. This pavement mosaic near the entrance of the Basilica of St. Reparatus at Orleansville (modern Chlef, Algeria) measures approximately 2.4 meters wide. Documentation sources: Saward 2003, Kern 2000, Matthews 1922. The same seven-circuit topology appears at this site as at every other classical labyrinth on Earth.
The labyrinth is one of several hundred sites of this type catalogued globally; each preserves the same unicursal walking-pattern with regional variation in scale, material, and date.