Looks like it could be a calendar or zodiac in Temple form:
https://news.artnet.com/art-world/kastelli-crete-minoan-monument-2500064
The articles didn't say if the inner cross was aligned with the cardinal directions or the equ/sol signs, but it looks like the outer-most part of the main dark circular depression had 18 sections. Could it be the Ra/Ke cycle?
Chaldeans had 18 houses in the heavens related to the moon. SOme people try to equate these to nakshatras but they are not the same. I think the 18 has to do with the eclipse cycle, so as there are 18 cycles of eclipses in a circle of rahu and ketu transits, it makes sense to have an 18 fold division of space just as we have a 27 fold for moon and 12 for sun. It would really be something wonderful and useful to reconstruct a useable 18 section cirlce in respec to this. The symbols for doing this are in the Mul Apin, the old CHaldean astronomy book that gives the names of the 18 houses.
@ernst Even in North America there are large "calendars" or zodiac creations which include 13-month, and/or 18-fold divisions with outer 28 sections like the lunar mansions. I think these were discovered around the Canada-USA border.
Didn't the Babylonians originally have 18 constellations as well, though sidereal? Eclipses were important to them.
the names of these were: The Stars, the Bull of Heaven, teh true sheperd of anu, the old m an, the crook, the great twins, teh crab, the lion, the furrow, the scales, the scorpion, pabilsag, the goat fish, the great one, the tails, the swallow. The frustrating thing about the Mul Apin text is that the risings of these stars is said to happen on certain calendar dates and the calendar used is a tropical calendar, so these dates would only apply to the rising during one particular century and there is no mention of ayanamsa to correct these dates. So it appears that the chaldeans had no knowledge of precession at this time.