This is the archaeological site of Olympia. It is an Unesco WHS. Although my parents are from a nearby village, it's been years since I last visited it.
Olympia (Greek: Ολυμπία, older transliterations, Olimpia, Olimbia), a sanctuary of ancient Greece in Elis, is known for having been the site of the Olympic Games in classical times, comparable in importance to the Pythian Games held in Delphi. Both games were held every Olympiad (i.e. every four years), the Olympic Games dating back possibly further than 776 BC. In 394 AD, ( after exactly 1170 years ) emperor Theodosius I abolished them as they were then considered reminiscent of paganism. The first olympic games were in Olympia in honor of Zeus.
The sanctuary, known as the Altis, consists of an unordered arrangement of various buildings. Enclosed within the temenos (sacred enclosure) are the Temple of Hera (or Heraion/Heraeum) and Temple of Zeus, the Pelopion and the area of the altar, where the sacrifices were made. The hippodrome and later stadium were also to the east.
Olympia is also known for the gigantic ivory and gold statue of Zeus that used to stand there, sculpted by Pheidias, which was named one of the Seven Wonders of the Ancient World by Antipater of Sidon. Very close to the Temple of Zeus which housed this statue, the studio of Pheidias was excavated in the 1950s. Evidence found there, such as sculptor's tools, corroborates this opinion. The ancient ruins sit north of the Alfeios River and Mount Kronos (named after the Greek deity Kronos). The Kladeos, a tributary of the Alfeios, flows around the area. Its located in the part of Greece which is called Peloponesse. In Ancient Greece, Olympia was sacred ground to the Greeks.