However, it seems the tide is turning. Local authorities are cracking down on illegal labor recruitment, and land-hungry developers have set their sights on Longhua. Now, working in cities around Shenzhen appears to be losing its allure among migrant workers who have to choose between heading home and hanging on.

"This winter, Longhua has become a whole lot quieter as the city planners clamped down on an illegal web of job recruitment in Sanhe and renovated nearby urban villages," said Fang Zhaozhao, a longtime Longhua resident. "This may be just the tip of the iceberg."

Longhua is at the mercy of change as Shenzhen evolves beyond its manufacturing roots and looks to high-tech industries and the high-end service economy for future growth. For unskilled workers, this may herald the end of a better life far from home in Shenzhen - a top-tier metropolis that was essentially built on migrant labor.

The sprawling city of 12 million people has seen just 34 percent of its population granted permanent residence, or hukou, under the national household registration system. Those without hukou are usually migrants who left their homes in search of better prospects in southern China's Pearl River Delta - the country's traditional manufacturing heartland which offers all sorts of labor-intensive job opportunities.

Scratching a living

For decades, Shenzhen has been a vital part of the global supply chain as foreign enterprises outsourced their businesses in search of a cheaper, sustainable workforce and lower production costs. That allowed migrant workers to eke out a living in the city and feed their families in the impoverished inland provinces.

At the turn of the century, the city's migrant worker population peaked in the downtown. As manufacturers arrived, such as Foxconn Technology Group which relocated its largest factory at the Longhua Science and Technology Park and set up a recruiting station at Sanhe, Longhua became a new congregation point for migrant workers.

It became a magnet and transfer station for unskilled laborers across Shenzhen and nationwide.

Located in Bao'an district - one of two areas formerly outside the Shenzhen Special Economic Zone - Longhua is one of just a few places in the city with a plentiful supply of cheap labor and rock-bottom living costs.

Xu Bin works at an electronics factory in Shangtang, just two metro stops from Sanhe.