"Kubla Khan" by Samuel Taylor Coleridge

After reading the poem "Kubla Khan" by Coleridge two things called my attention. The first one was that Coleridge was under the effect of opium when he wrote this poem. It is said, that this poem was a hallucination that he had due to the drug. It is really weird, at least for me that a famous poet writes under the opium effects, but many people celebrate the fact that he was capable of writing such a piece of work under this effect.

The second thing is that the writer really cares about nature. I understand that romanticism was focus on nature, but this poem is only about nature. The poem was really difficult to understand, even though we read it in Spanish too. He talks about rivers, forests, gardens, and so on. I imagine that his hallucination was about a castle which was located in a wonderful forest, full of trees and animals around it. He might want to live in a place like that.
It is said that his poem is not finish because he received a visitor while he was writing. I believe that it is ok the way it is.