In the itinerary of Pausanias, the ἄδυτα of the oracular temples appear to have been sunk beneath, and under the basement or floor of the building. This was so generally the case, that in _Bœoticis_, the word _adytum_ is used as synonymous for the _cave_ of Trophonius. _In Corinthracis, cap._ i. the entrance and passage to the adytum of Palæmon at Chronium, is represented as subterraneous; ἔστι δὲ καὶ ἄλλο ἄδυτον καλούμενον, κάθοδος δὲ ἐς ἀυτὸ ὑπὸ γεως. edit. Kuhn. p. 113, and in the _Achaicis_, the entrance of the adytum of the temple of Minerva, at Pellené, is from under the base of the statue of the goddess, and the recess is hyperbolically represented, as penetrating to the very centre of the earth. The purposes of these crypts, or concealed recesses in the oracular temples, may readily be surmised: and to conduct their oracle with proper mystery and imposition of respect, was a necessary policy in the priesthood, to prevent any visit or examination of these hallowed places: the hand of the deity was denounced as punishing the trespasser with instant death. Of the many examples that offer, we will take one from _Egypt_: Pausanias in _Phocicis_, mentions, “That a Roman Prefect having from impious curiosity, sent a person to inspect the _adytum_ of Isis at Coptos, the unhallowed intruder was struck dead on the spot. The oracle was given _ex adyto_. · · · · isque adytis hæc tristia dicta reportat. Virg. Æn. l. ii. v. 115. It was given too _imo adyto_, or as others express it, from the _depth_ of the adytum. Nec dum etiam responsa Deûm monitusque vetusti Exciderant, voxque ex adytis accepta _profundis_ Prima,—“Lycurge dabis Dircæo funera bello.” Stat. Theb. l. v. 645. Diod. Sic. lib. xvii. says, that when Alexander required an oracle from Ammon, the chief priest retired back to the sanctuary or holy place, and gave the answer, _ex adyto_; so the Latin version of Wesselingius expresses it: in truth, there is no Greek word in the original, immediately corresponding with _ex adyto_; yet the priest retiring εις σήκον, _i. e._ to the fane or secret recess of the temple; his giving the oracle from such secret recess may be implied. Applying the accounts of the _adytum_ to the building under consideration, it may be observed, that to form such recess, the rock rising in the centre of the enclosure described at Siwah, offered a peculiar accommodation to the architect. The soil around is represented as wet and marshy, and not therefore suited to excavation. The erecting the Προνὰος, or forepart of the temple, on the elevation of the rock, admitted of the interior end or _penetrale_ being built over a crypt, or artificial cave of eight feet deep, suitable to the purpose and mysteries of an oracular temple.