You can see remnants of the wall in the east side of town. Be warned: these mounds are not terribly impressive.
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郑州文庙
The Zhengzhou Confucius Temple is a historical building complex dedicated to Confucius. The first temple was built here in the first century AD, and it has been rebuilt several times after being damaged or destroyed by wars and fires. The Dacheng Hall, dating from the Qing Dynasty, is the main historic building in the complex, while many of the other buildings are modern reconstructions. The Dacheng Hall, which dates from the Qing Dynasty, is the main building of historical value. The other buildings that make up the complex are largely modern reconstructions.
二七纪念塔
Museum inside a rather garish double pagoda that looms over February 7 Square. Inside there are exhibits explaining the city's development.
人民公园; Rénmín Gōngyuán, Renmin Park
Has a theme park inside with a quaint Ferris Wheel that is worth riding.
郑州世纪欢乐园
It is quite a huge amusement park. Be aware most rides have a 90-kg limit for anyone using them, sometimes staff can be strict and refuse to let you ride even after you have paid to get in.
Fu Tower, 中原福塔
This 388-metre high tower is the 10th tallest tower in the world and has great views of the city. On the third and fourth floors of the observation deck, you can see the largest panoramic painting in the world.
如意湖; Ruyi Hu
The centrepiece of the Zhengzhou New Area, surrounded by an impressive ring of modern apartments, malls and office towers, including the Henan Arts Centre, and crowned by a JW Marriott designed like a Chinese lantern. The area is lit up in a charmingly tacky fashion at night.