It is suggested that you can take the Guangzhou-Shenzhen high-speed train to Shenzhen. The places you can visit are splendid china, Folk Culture Village, Window of the World, Happy Valley, Meisha, Zhongying Street, etc. These are all very suitable for taking children to play. It takes more than an hour from Guangzhou to Shenzhen by high-speed train, and then you can go to these places by taking the Shenzhen subway. Shenzhen can go back and forth in one day, just go to Guangzhou in the morning and come back at night.
In addition, Humen Bridge in Humen, Dongguan, Weiyuan Island, Weiyuan Fort, Shajiao Fort and Humen Park can also be reached. However, children in primary school may not be very interested in these.