The Temple of Hera II (called the 'Temple of Neptune' by 18th-century travelers who named it wrong) was built around 460 BC - same era as the Parthenon. The Parthenon has been blown up, stripped, reconstructed, and debated for centuries. The Temple of Hera II has 34 columns still standing, most of the entablature intact, and has never required major reconstruction. At Paestum Archaeological Site (Via Magna Graecia 919, open Apr-Aug 8:30am-7:30pm, last ticket 6:50pm, €15 adult covering temples + museum + Velia, valid 3 days), stand at the southern end and count the columns along the long side (you'll count 14). Then count the short side (6). This 6x14 Doric colonnade formula was the standard of Classical Greek temple design. The city was named Poseidonia after Poseidon, settled by colonists from Sybaris - the same pleasure-seeking city Croton destroyed in 510 BC. The golden-ochre limestone changes color as the sun moves - arrive early morning or late afternoon for the most dramatic light.
🔄 BACKUP: The site has three temples in total - if time is limited, prioritize Hera II (center) and Hera I (south, called 'the Basilica'). Both are 6th-5th century BC. The Temple of Athena (north) is slightly smaller but equally ancient.