If you only have time to explore part of the Parco Valle dei Templi, make it the eastern zone, where you'll find the park's three best-preserved temples. Overlooking the eastern ticket office, the 5th-century-BC Tempio di Hera , also known as the Tempio di Giunone (Temple of Juno), is perched on the edge of a ridge. Though partly destroyed by an earthquake in the Middle Ages, much of the colonnade remains intact as does a long altar, originally used for sacrifices. The traces of red are the result of fire damage, most likely during the Carthaginian invasion of 406 BC.
From here, the path continues westwards, past a gnarled 800-year-old olive tree and a series of Byzantine tombs built into the city walls, to the Tempio della Concordia (Temple of Concord). This remarkable edifice, the model for Unesco's logo, has survived almost entirely intact since it was constructed in 430 BC. There are several reasons why it has survived while other temples have not, one being that it was converted into a Christian basilica in the 6th century and the main structure was reinforced. The principle reason, though, is more down to earth. Beneath the hard rock on which the temple stands is a layer of soft clay that acts as a kind of natural shock absorber, protecting it from earthquake tremors. Whether the Greek engineers knew this when they built the temple is the subject of debate but modern scholars tend to think they did. In 1748 the temple was restored to its original form and given the name it's now known by. The last of the zone's temples, the Tempio di Ercole , is the oldest, dating from the end of 6 BC. Eight of its 38 columns have been raised and you can wander around the remains of the rest. Down from the main temples, you can see a little temple set on a high base. This is known as the Tomba di Terone , although it dates to 75 BC, about 500 years after the death of Theron, Agrigento's Greek tyrant.
