The classical world, or classical antiquity, is a traditional definition describing the cultures of the Mediterranean area, from Classical Greece to the end of the Roman Empire. In this lesson we shall speak about Greek sacred architecture, which is famous for hundreds of magnificent temples, built over the course of several centuries. Although there are important regional and chronological distinctions in the layout and in the column orders of the temples, these buildings were always based on the same conception: an imposing rectangular construction adorned with columns on the façade. A Greek temple was meant to occupy a natural place with an obviously man-made feature, and it was to be admired from the outside only. Admission was reserved to priests and public rites were celebrated outside, on the altars in front of the temple; religious occasions included festivals, processions and long rituals. The interior of the temple was, strictly speaking, the home of the god, represented by a statue. Here we shall concentrate on a specific case, that of the Greek temples of Sicily. The foundation of the Greek colonies in the Mediterranean began as far back as the 8th century BC. They were set up for commercial reasons, but also, in some cases, for political or demographic reasons. Southern Italy was one of the preferred destinations, and Greek culture was exported into Sicily with the foundation of important colonies such as Siracusa, Agrigento (ancient Akragas), and Gela. Hand in hand with culture, the Greeks exported religion, and consequently several magnificent temples were constructed. Even today, many Greek temples of Sicily stand as unequalled masterpieces; among them Segesta, the Selinunte temples, and the Valley of the Temples at Agrigento. The orientation of a temple is defined as the direction of the main axis from inside looking out, which is the direction in which the statue of the god was looking at. Almost all the temples of Sicily are orientated within the arc of the rising Sun, so that the Sun rises in alignment with each of them on two specific days of the year or one day, for those solsticially oriented. However, as usual, understanding ancient minds is not an easy task, so that in many cases also other factors must be taken into account. For instance: many temples – like the Aesculapius sanctuary and the world famous Concordia Temple, both at Agrakas – are perfectly oriented to the true east. But the horizon is uneven, so that the corresponding days are not the equinoxes, but the end of March and the middle of September. Since those dates do not look as relevant in any way, we are let to think that these temples were designed and built to be oriented to the cardinal points. Of course the front points to the East. In other cases, it was the landscape to dominate over the solar orientation. This occurs, for instance, for another magnificent ensemble of Sicilian temples, that of the Selinunte hill. The temples are virtually parallel to each other and share similar orientations to the rising Sun at the end of February/ mid October with an azimuth of ~96°. However, a closer inspection reveals that the axis of the first temple points to a particular feature on the distant horizon: a prominent peak, which acts as a marker for a mountain – over the seaside town of Sciacca – sacred since Neolithic times thanks to the presence of hot springs. The urban plan and the temples of Selinunte downtown also share the same orientation. So the peak is a likely candidate as the topographical target which influenced the positioning and the orientation of the monument. Finally, of course, all Greek temples oriented to the rising Sun are also oriented towards the stars, which eventually had the same declination at the times of their construction. A possible, specific interest by the builders in this kind of stellar target must be investigated separately case by case. Here for instance we are in the so-called Juno temple in Akragas, of which we do not know the attribution, that is, the god to whom it was dedicated. The temple is orientated at 82 degrees. With an horizon height of 2 degrees this corresponds to a declination about 7 degrees, that of the Sun around the mid of April and the beginning of September, but also – of course only at the time of construction in the 4th century BC and not now – of the small constellation of the Dolphin, sacred to Apollo. May this be an astronomical hint, suggesting that this magnificent temple was indeed dedicated to Apollo?