I came across a new word today in my inbox – hypaethral (\hye-PEETH-rul\).  Webster defines this adjective as:

1  : having a roofless central space
2  : open to the sky ((“hypaethral.” Merriam-Webster Online Dictionary. 26 November 2008
<http://www.merriam-webster.com/dictionary/hypaethral>))

What caught my interest was that this word is applied mostly to ancient temples.  The example sentence that was given was:

During our tour of Egypt, we visited the hypaethral temple of Philae, which was dismantled and relocated after the construction of a dam caused its original site to be submersed.  ((Email – “hypaethral: M-W’s Word of the Day,” November 26, 2008.))

Webster’s given etymology of the word explains why it is often associated with temples:

Ancient Roman architect and engineer Vitruvius used the Latin word “hypaethrus” to describe temples in which the “cella” (the part of the temple housing an image of the deity) was wholly or partially uncovered. “Hypaethrus” is a word sculpted from the Greek prefix “hypo-,” meaning “under or beneath,” and the Greek word “aithēr,” meaning “air or heaven.” In the late-18th century, English classicists adopted the remodeled form “hypaethral” in their writings of ancient architecture. Another adjective that they occasionally employed is “cleithral,” which designates temples having roofed central spaces. (“Cleithral” comes from “kleithra,” the Greek word for “lattice.”) ((ibid.))

In other words, the innermost sanctuary of ancient temples (known in the Israelite tradition as the Holy of Holies) was sometimes open to the sky, hyp-aethral, or “under heaven.”  This was likely due to the temples’ often association with the cosmos.  While although the “Hypaethral Temple” at Philae may not have actually been open to the sky in its heyday, a couple examples of this scenario might be found in Stonehenge and Göbekli Tepe.

Read more in the Wikipedia article on hypaethral.  Dr. William R. Long also has a good description and study of this word, including this interesting quote from Henry David Thoreau ((Elder Perry spoke of this philosopher in the last General Conference)), who used the term figuratively:

Shall the mind be a public arena, where the affairs of the street and the gossip of the tea-table chiefly are discussed? Or shall it be a quarter of heaven itself – an hypaethral temple, consecrated to the service of the gods? ((Hentry David Thoreau, “Life without Principle.”))