Visitors enjoy themselves at the Bund in east China's Shanghai Municipality, July 13, 2013. The Air Quality Index released by Shanghai Environmental Monitoring Center Saturday morning was 42, a level suitable for outdoor activities, which attracted many people to go outside and enjoy themselves. (Xinhua/Lai Xinlin)

Photo taken on July 12, 2013 shows the cultural heritage site of Melaka in Malaysia. Melaka and George Town, historic cities of the Straits of Malacca, were inscribed onto the list of UNESCO World Heritage Site in July 2008. (Xinhua/Chong Voon Chung)

Lotus flowers blossom at the scenery spot of the Daming Lake in Jinan, capital of east China's Shandong Province, July 11, 2013. (Xinhua/Guo Xulei)

Students visit the Garden Expo Park in Beijing, capital of China, July 9, 2013. The 9th China (Beijing) International Garden Expo is held here from May 18 to Nov. 18, 2013. (Xinhua/Wang Xibao)

Photo taken on July 9, 2013 shows the scenery of Hongcun Village, known as "a village in the Chinese painting", in Yixian County of Huangshan City, east China's Anhui Province. (Xinhua/Shi Guangde)

Photo taken on July 9, 2013 shows the scenery of the Baotu Spring in Jinan, capital of east China's Shandong Province. The undergroud water level of the Baotu Spring, a famous scenic spot in Jinan, has dropped to 28.11 meters, lower than the yellow warning line of 28.15 meters. (Xinhua/Guo Xulei)

The Siena Cathedral is seen in the historic center of Siena, Tuscany of Italy, July 7, 2013. The historic center of Siena was inscribed onto UNESCO's World Heritage List in 1995. The city is famous for its medieval cityscape and the horse race Palio, attracting over 150,000 visitors every year. (Xinhua/Xu Nizhi)

Two visitors take pictures of rape flowers in Menyuan Hui Autonomous County, northwest China's Qinghai Province, on July 9, 2013. More than 500,000 mu (about 33,000 hectares) of rape flowers blossomed since July and attracted many tourists there. (Xinhua/Wu Gang)

A fisherman fishes on the Xiaodongjiang River in Zixing City, central China's Hunan Province, July 7, 2013. (Xinhua/He Maofeng)

Lotus flowers blossom at the Humble Administrator's Garden in Suzhou City, east China's Jiangsu Province, July 7, 2013. (Xinhua/Hang Xingwei)

Two impalas fight against each other at Crescent Island in Lake Naivasha, Kenya, July 7, 2013. (Xinhua/Zhang Weiyi)