Separating the S end of the plain of Athens from that of the Mesogaia to the E is the mountain range of Hymettos. About 20 km long, and broken into two parts by a pass that crosses E-W from N of the civil airport at Helleniko to Koropi, ancient Sphettos, the larger N section reaches a height of over 1000 m along its whale-back ridge, while the S, also called Anhydros (waterless), consists of several peaks, the highest being 774 m.
In antiquity Hymettos was famous for honey and marble, and the scars of the worked-out quarries can be seen concentrated for the most part on the W slopes for a distance of 3 km S from Kaisariani. The bare summit performed a different function: even as today, it gave the Athenians a reliable indication of weather by the presence, or absence, of threatening clouds (Theophr. De sign. temp. 20). Less than a km N of the highest point, excavations have disclosed two crude rectangular foundations, possibly for altars, the one probably dedicated to Herakles, the other most likely to Zeus. Near the latter was a pit full of sherds, the bulk either Geometric and archaic or Late Roman. A large stele was also found with cuttings for a small bronze statue, perhaps that of Zeus Hymettios mentioned by Pausanias (1.32.2). As for the altar ascribed to Zeus, its location makes it a suitable candidate for that of Zeus Ombrios described in the same passage. The altar of Zeus Epakrios (Etym. Magn. s.v. *)epa/krios *zeu/s) should have been on the very summit. All ancient remains, however, have been recently obliterated by military building operations.
Another, and better preserved, pair of foundations has been cleared at the Church of Prophet Elias, a little more than 3 km due S of the summit, on the E slopes of the peak Zeze, overlooking the Mesogaia, with the ancient deme of Sphettos immediately to the E below. Beneath the church are the remains of a small temple, consisting of a cella with pronaos and opisthodomos. Twenty-five m away another temple of similar size and general disposition was discovered. Both were built in the 6th c. B.C. The one on the site of the church was apparently destroyed at the beginning of the 5th, restored in the second half of that century, and survived until Roman times. The other was destroyed in the 3d c. B.C. About midway between the two temples is a prominent natural rock, several m high, which may have served as an altar. No evidence exists for a firm identification of either temple.
Finally, there are two caves that deserve notice. Near the N end and on the mountain's E flank, 4 km from Liopesi, is the Lion Cave. Classical and Roman sherds found within it testify to its long use in antiquity; perhaps Pan was worshiped here. No doubt surrounds the deity honored in the second cave, the famous one of Pan on the S slopes overlooking Van. Inscriptions, sculpture, votive reliefs, and pottery make obvious the popularity in Classical times of this cult of Pan, Apollo, the Nymphs and Graces. Chief among the worshipers was Archedemos of Thera, a man of the 5th c. B.C. 'caught by the Nymphs,'; who carved in low relief an image of himself as a sculptor carrying pick-hammer and square. A millennium later, this cave was taken over by the Christians. (C.W.J. ELIOT) Wikipedia: https://en.wikipedia.org/wiki/HymettusWikidata ID: Q1232266Trismegistos Geo: 15653
Info: Princeton Encyclopedia
(Princeton Encyclopedia of Classical Sites, from Perseus Project)