Time has been kind to Nirukti: it stood almost wholly intact when Scorpion scouts discovered it in the early days of the Empire. The samurai who explored it recorded the carvings they saw there, recognizing them relics of a human tribe from before the fall of the Kami. They theorized the people who built the city had been so cruel and deceitful, they embraced the iconography and worship of the serpent, turning their backs on proper objects of reverence such as the Sun and Moon.
Asako Kinto has translated the name of the city on the map you have, labeling it as "Joy".