Seyuan Garden, built in 1924, is one of the largest botanical gardens in Nantong. The garden is home to more than 10,000 types of rare trees from over 200 species and is considered a "natural oxygen bar". [Photo/Langshan National Forest Park]

Seyuan Garden, Junshan Mountain, Jianshan Mountain, Green Valley City, and Zhouji Green Expo Garden in Nantong, East China's Jiangsu province will be open to the public for free on July 1 in celebration of the 100th anniversary of the founding of the Communist Party of China.