The Seven Wonders of the World or the Seven Wonders of the Ancient World refers to remarkable constructions of classical antiquity listed by various authors in guidebooks popular among ancient Hellenic tourists, particularly in the 1st and 2nd centuries BC. The most prominent of these, the versions by Antipater of Sidon and an observer identified as Philo of Byzantium, comprise seven works located around the eastern Mediterranean rim. The original list inspired innumerable versions through the ages, often listing seven entries. Of the original Seven Wonders, only one—the Great Pyramid of Giza, the oldest of the ancient wonders—remains relatively intact. The Colossus of Rhodes, the Lighthouse of Alexandria, the Mausoleum at Halicarnassus, the Temple of Artemis and the Statue of Zeus were all destroyed. The location and ultimate fate of the Hanging Gardens are unknown, with speculation that they may not have existed at all.