Shenzhen became the first Chinese city with a GDP density or GDP per square kilometer surpassing 1 billion yuan ($156 million), according to a report by the yicai.com app.

The GDP density of Shenzhen city, not including Shenzhen-Shanwei Special Cooperation Zone, reached 1.12 billion yuan, more than all other cities in the Chinese mainland.

Shanghai, with a 475 million yuan GDP per square kilometer in 2017, took the second spot on the top 10 GDP density list, followed by Dongguan, Guangzhou and Xiamen.

GDP density, or GDP per square kilometer, is a measure of economic activity by area and it reflects a place's economic density and vitality.

Let's take a look at all the cities on the list.

No 10 Nanjing