Each year, when the summer solstice comes around, the Guangzhou Tropic of Cancer Landmark Tower draws the attention of visitors, particularly the astronomy enthusiasts. 

The summer solstice is the 10th solar term of a year according to the traditional Chinese lunar calendar, which divides the year into 24 solar terms. It marks the midsummer of a year. 

Located in Conghua district in Guangzhou, the capital city of Southern China's Guangdong province, the Guangzhou Tropic of Cancer Landmark Tower opened to the public on the summer solstice of 1986. 

It is the tallest landmark tower to stand on the Tropic of Cancer anywhere in the world. The Guangzhou municipal government set up a stone to mark the boundary between the tropical zone and the northern temperate zone. Every year on the summer solstice, the sun will shine down vertically along the Tropic of Cancer. At noon that day, the interesting phenomenon of no shadows being cast will appear gradually from east to west Guangdong, through which the Tropic of Cancer passes.

On the day of the summer solstice each year, amateur astronomers and geography enthusiasts gather at the tower to witness and record the shadowless moment around noon time. Conghua has also organized events promoting the landmark and conducting science education around the subject. 

The unique geographical location of Conghua also brings advantages to its agricultural industry, especially the planting of lychee. The moderate weather and abundant rainfall provide perfect conditions for lychee growing, and together have earned Conghua the title of the "hometown of lychees in China".