The Temple of Olympian Zeus, also known as the Olympieion, is an ancient temple located in Athens, Greece. It was dedicated to the god Zeus, the king of the gods in Greek mythology. Construction began in the 6th century BCE but was not completed until the 2nd century CE during the reign of the Roman Emperor Hadrian. Originally, the temple featured 104 colossal columns, of which only 15 remain today. The structure was one of the largest temples in the ancient world, showcasing the grandeur of Hellenistic architecture. The temple's ruins are a popular tourist attraction, reflecting the rich history of ancient Greece.