Analysis of Mona Lisa

Yon strange blue city crowns a scarped steep
No mortal foot hath bloodlessly essayed:
Dreams and illusions beacon from its keep.
But at the gate an Angel bares his blade;
And tales are told of those who thought to gain
At dawn its ramparts; but when evening fell
Far off they saw each fading pinnacle
Lit with wild lightnings from the heaven of pain;
Yet there two souls, whom life’s perversities
Had mocked with want in plenty, tears in mirth,
Might meet in dreams, ungarmented of earth,
And drain Joy’s awful chalice to the lees.