We don't have synonyms for eternal city yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are eternality.
(n) :
Nickname for Jerusalem: a city in West Asia; the claimed capital cities of Israel and Palestine.
(n) :
(historical) Former nickname for Kyoto: a major city in Japan, during the period when it was named Heian-kyō and served as the capital of Japan; c. 800–1000 CE.
(n) :
Nickname for Jerusalem: a city in West Asia; the claimed capital cities of Israel and Palestine.
(n) :
(historical) Former nickname for Kyoto: a major city in Japan, during the period when it was named Heian-kyō and served as the capital of Japan; c. 800–1000 CE.