Here is a summary of the poem:
The poem begins with Wilde describing Ravenna as a "city of marble and gold," and he praises the city's "towers and domes" and its "churches and palaces." He then goes on to describe the city's history, including its sacking by the Visigoths in 493 AD and its subsequent decline.
Despite its decline, Wilde still finds Ravenna to be a beautiful city, and he admires the city's many churches and mosaics. He is particularly impressed by the mosaics in the Church of San Vitale, which he describes as "a miracle of art."
Wilde also reflects on the transience of life and the inevitability of death. He notes that even the most beautiful things in life, such as the city of Ravenna, will eventually fade away. However, he also finds comfort in the fact that art can transcend time and death.
The poem ends with Wilde expressing his hope that his own works of art will be remembered long after he is gone. He writes: "I leave my works to the unknown years,/To the eyes that shall behold them after I am gone."
"Ravenna" is a beautiful and moving poem that celebrates the city of Ravenna and the power of art.