And, little town, thy streets for evermore Will silent be; and not a soul, to tell Why thou art desolate, can e'er return. (lines 38-40)
It’s weird to image a town that will never have people in it. Without people, wouldn’t it just be a bunch of buildings? The word "desolate" has a slightly negative connotation, as if we were supposed to identify with the spurned and abandoned town. Also, the word "silent" reminds us of the urn, the adopted child of silence. But unlike the town, the urn gets to interact with humans because it exists in a transient world. Without transience, things that are abandoned cannot be found again.
When old age shall this generation waste, Thou shalt remain, in midst of other woe (lines 46-47)
The poem speeds up at the end, reminding the reader of his or her own transience, and of the mortality of the speaker, by now long dead. This poem, like the urn, has continued to speak to new generations and address new problems. How are our "woes" different form those of Keats’s audience?