'splendid city' is a correct and usable phrase in written English.
You can use it to express admiration or approval for a city's beauty. Example: "New York City is a splendid city. The bright lights, busy streets and city skyline create a truly unique atmosphere."
The splendid City Varieties, in Leeds, has been in constant artistic use.
The hitherto obscure town of Ghazna became a splendid city, as did the second capital at Bust (Lashkar Gāh).
My time on the river was the perfect contrast to two days in Paramaribo, a splendid city.
For the grime of New York, and the grime I might make of my body in that splendid city.
Billboards extol the virtues of what one propaganda poster calls "the most beautiful and splendid city in the world".
Hangzhou is one of China's most attractive cities — Marco Polo described it as "without doubt the finest and most splendid city in the world".
The port flourished into one of Asia's most splendid cities before disease, vice and trade competition sank its fortunes.
Ephesus, Miletus, Smyrna, and Chios were among the most splendid cities of the Roman world and continued to flourish in Byzantine times.
Here were hitherto unknown civilizations that not only were populous and spread over vast territories but also had splendid cities and complex forms of government, arts, crafts, and religious practices.
In particular, Greek and Latin scholarship was collected in great libraries in the splendid cities of Córdoba, Sevilla (Seville), Granada, and Toledo, which became major centres of advanced scholarship, especially in the practical arts of medicine and architecture.
The incandescence of this rich history amid a teeming metropolis, however, can leave even the most seasoned traveler too dazzled to truly appreciate one of the world's most splendid cities.
