The temples of the later 5th century BCE are of a size similar to that of mainland temples, with stylobates measuring 16-17 x 38-40 m, and have a standard colonnade of 6 by 13 columns (although elsewhere in Sicily 6 by 14 was more frequent) and a cella with pronaos and opisthodomos; Sicilian characteristics include high foundations with four steps, closely spaced colonnades with heavy columns and frequent use of double angle contraction, wide steps in the front and omission of columns in the cella. The temples D (to Hera Lakinia) and F (Concord) in the south-east of the town (ca. 450 BCE and 425 BCE respectively) differ only in minor details and a more accurate execution in the later building. Both have double angle contraction (Temple D only at the eastern front). Temple F is one of the best-preserved ancient temples in the world. Temples D and F, together with the Temple of Zeus and the so-called Temple of Herakles, are arranged scenographically on a ridge at the southern boundary of the town (Valle dei Templi).