It appears that the earliest version of the Tripura myth ("three-city"; not to be confused with the real state of Tripura), appearing in the Krishna Yajurveda, does NOT have the different "citadels" of the city in different worlds, for example the highest citadel of gold being located in the heavens and the lowest of iron located on earth or in the underworld.
The oldest version also lacks the motif of the three citadels only being able to be destroyed once every 1,000 years, when they all align.
To me, this suggests a kernel of historical narrative which has since taken on a more mythologized and symbolic bent in later versions.
Also note in the post above this one, according to wikipedia, the protection of Mayasura bears striking resemblance to the protection of Noah and other mythological survivors of cataclysms.
The oldest version also lacks the motif of the three citadels only being able to be destroyed once every 1,000 years, when they all align.
To me, this suggests a kernel of historical narrative which has since taken on a more mythologized and symbolic bent in later versions.
Also note in the post above this one, according to wikipedia, the protection of Mayasura bears striking resemblance to the protection of Noah and other mythological survivors of cataclysms.