Runan: An ancient place name, located in Henan Province, is a place with a long history and culture.
Heart leisurely: inner sadness and anxiety.
In the sky: in the sky, it can be understood as "the end of the sky", which means something that cannot be reached and touched.
Sorrow: A feeling of sadness and sadness.
On the whole, the sentence "I am in the heart of Runan, and I am sad on this day" can be understood as: the author feels extremely sad and depressed in Runan, a distant and untouchable place.