John, I've checked-out your Vardzia link. Very interesting and educative.
I've learned Vardzia is a cave monastery on the side of the Erusheli River in southern Georgia near Aspindza on the left bank of the Mtkvari River. It was founded by Queen Tamar in 1185.

The monastery was built as a protection against the Mongols and consisted of more than six thousand apartments in thirteen floors. The city included a church, a throne room, and a complex irrigation system with watered terraced farmlands. The only access to the complex was through the few well-hidden tunnels near the Kura.

An earthquake in Samtsche destroyed about two-thirds of the city in 1283, exposing the caves from the outside and leading to the collapse of the irrigation system.

I've understand too that five monks still live in the Vardzia cave monastery.

You probably didn't show them in your wonderful render for respect's sake. It could also be that they were working on the innovations as mentioned in your title.

As usual, your post was provided with an appropriate quote and music links. Very well done again!

Very thought provoking. I see two wise owls looking back at me. Mesmerizing music

I see the Bouncers at the door..Trouble looms..R.

Thought provoking and I found the info from Mr. C. very interesting.
tigs=^..^=