This is the 7452nd most frequent Chinese word.
衡阳
Hengyang: A city in Hunan Province, China.
衡阳 is used here as a proper noun referring to a city name.
衡阳位于湖南省，是一个风景优美的城市。
Hengyang is located in Hunan Province and is a city with beautiful scenery.
衡阳 is used here again as a proper noun, specified in the context of travel.
你今天要去衡阳吗？
Are you going to Hengyang today?
The word 衡阳 denotes the place, highlighting its attributes and cultural significance.