Complex sentence: The Temple of Jupiter--once wrongly credited to Helios--lay at the western end of the "Great Court" of Roman Heliopolis, raised another on a platform reached by a wide staircase.
Split into simpler sentences: The Temple of Jupiter--once wrongly credited to Helios--lay at the western end of the "Great Court" of Roman Heliopolis. It raised another on a platform reached by a wide staircase.