Adytum

Let us now with minds free of paſſion, enter the adytum with an intent to find out its true figure, to examine what it really was, and what it is. […] This point is properly the door-way or entrance into the adytum, as a wicket or little door, whilſt the jambs of the hithermoſt trilithons preſent themſelves, as the greater door, of about 40 feet wide, 25 cubits. […] [T]he more ſacred part of the temple at Hierapolis anſwering to our Adytum, had no door, tho' none enter'd therein but the chief prieſts.

Source: wiktionary

At the diſtance of about forty ſtadia from this temple of Æſculapius, there is an incloſure; and in it there is an adytum ſacred to Iſis. This is the moſt holy of every thing which the Greeks conſecrate to this goddeſs. For the Tithoreans neither think it proper to take up their reſidence there, nor to ſuffer any to enter the adytum, except ſuch as the goddeſs Iſis informs them by a dream ſhe thinks proper to admit.

Source: wiktionary

Although it was the custom for the priestesses to affect a holy fury, a species of temporary insanity, in the delivering of their oracles, yet it was also the custom to write them on the leaves of trees, and to deposit them at the entrances of their caves, or the adyta of their temples; and it was the object of the devotee to secure them before they were dispersed by the winds; […]

Source: wiktionary

The adytums or inner circles of Abury and Stonehenge bear such an analogy to the holy of holies in Solomon's temple, as to induce the belief that they were formed subsequently to the temple of Jerusalem, with which the Tyrian workmen were quite familiar.

Source: wiktionary