From Wikipedia

The Seven Wonders Of The Ancient World

The Seven Wonders of the World (or the Seven Wonders of the Ancient World) is a well known list of seven remarkable constructions of classical antiquity. It was based on guidebooks popular among the ancient Hellenic tourists. The most prominent of these, the versions by Antipater of Sidon and an observer identified as Philon of Byzantium, is composed of seven works located around the Mediterranean rim. In turn, this “original” list has inspired innumerable versions through the ages, often in keeping with the limited number of seven entries.