Ah, there is that rather fetching light in Shen Yuan's eyes. Really, he will make someone very happy one day, Lan Xichen is certain of it.

"I have," he affirms with a nod for emphasis. "Though from what I've also heard, its ruins can be found outside the city - that it is, in fact, a past civilization of this world."

Which is why Lan Xichen believes this world to be old. But he raises a brow, watching Shen Yuan with interest now, because it seems like something's been cooking in that head of his. If he had a concept of 'meta knowledge' he would probably think it could be applied here.

Alas, he does not.

"How has Shen-gongzi come to suspect it is only a few years old?"