Question: what does Tianmen and Heshan, Guangdong have in common?
Sentence (from "Heshan, Guangdong"): Heshan, formerly romanized as Hokshan, is a county-level city of Jiangmen City in the southern part of Guangdong Province, China with a total land area of 1108.3 km2 and a population of 360,000.
Relevant evidence: Yes