On my third try, after much searching, I finally found Tbilis’s Atashgah, or Fire Temple. The two LonelyPlanet maps show slightly different locations for the Atashgah, both of which are close but slightly too far East. You can’t access the Atashgah from the path to the Narikala fortress; rather you must come to it by going up into the nameless little streets South-East of the Jvaris Mama church, then taking the steps up to the Meheti church, then going 100 m East.
I finally spotted the Atashgah because I noticed a self-congratulatory sign listing various worthy groups that were funding some restoration program. But of what? Then I realized the rather dull looking redbrick building matched the descriptions I’d read, so I checked with a workman and yes, this was it!
It is a strange structure: roughly a 20ft sided cube, under active restoration both inside and out. There is an entrance doorway, and arched sides but no windows. The roof is gone and there is a tree growing inside. There is what seems to be a fire pit in the center. I paid my respects, and gently asked the Lord of Fire to be kind to California (currently plagued by wildfires).
This is believed to an authentic Zoroastrian Fire Temple, established during the short-lived Persian occupation of Tbilisi in the 6th c AD. The Zoroastrians venerated fire as a pure element and would use the temple flame as a focus (or direction) to worship Ahura Mazda, the one universal god.
[ See also Tbilisi Ateshgah Revisited in 2010].