By no later than 776 B.C., a series of athletic competitions had commenced among representatives of Greek city-states, the precursor to the modern Olympic games that we have been enjoying these past two weeks. The games took place in Olympia, Greece (classed in T2—388 Arcadia to 323, Argolis to 323, Elis to 323, where Olympia is found in the including note). Or, if you don't care for that presumed genesis of the games' name, you may be interested in the mythological explanation given by the ancient Greeks of the games’ origin, which involved some of the gods who lived permanently on Mount Olympus (the "Olympian gods") engaging in various athletic competitions. If the dot on online maps is placed accurately, then Mount Olympus is just inside the borders of Thessaly and would be classed in T2—382 Thessaly to 23, Epirus to 323, adjacent Ionian Islands to 323. (Please don't ask me to make sense of why Olympia is in the west of Greece, but Mount Olympus is in the east.) The Olympian gods (and goddesses) themselves are classed in 292.211 Greek and Roman gods and goddesses, which is built from 292 Classical religion (Greek and Roman religion), plus 211 from 202.11 God, gods, goddesses, divinities and deities, following the instructions at 292.1–292.9 Specific elements; notice the class-elsewhere note at 292.07–292.08 Classical religion by specific culture (see 292.08 Greek religion), which reads, "Class specific elements regardless of culture in 292.1–292.9." (Because he didn't think the unexplained east/west difference of Olympia and Mount Olympus was confusing enough, Michael Panzer adds that the site of the ancient games was just north of Mt. Kronos, which is named after Kronos, the leader of the mythological Titans; the Titans were overthrown by the Olympians, led by Kronos' son Zeus, in honor of whom the ancient Olympic games were held.)
Olympia, Greece continues to play a unique role in the modern Olympic games, since it is from here that the Olympic torch is lit and begins its journey toward the place where the games will be played.
As Michael recently alluded to, the term "Olympiad" also derives from the games, where an Olympiad is a 4-year period. In ancient Greece, an Olympiad ran from one summer execution of the games to the next execution four years later. Since our modern games include both summer games (classed in 796.48 Olympic games) and winter games (classed in 796.98 Winter Olympic games), one of which takes place every two years, an Olympiad now runs from January 1 of the year in which the summer games are played, for four years. As a chronological unit, Olympiads are classed in 529.2 Intervals of time.