South of the nymphaeum, an elaborate staircase rises from the cardo maximus to Jerash's only cathedral. Little more than a modest Byzantine church, it was constructed in the second half of the 4th century on the site of earlier temples. At the height of its glory the cathedral consisted of a soaring basilica supported by three naves and it boasted a magnificent portal finely decorated with elaborate marble carvings. It's a fascinating insight into the many periods of Jerash's history.