19. Largest transport expansion

Beijing's first subway linking Fuxingmen and Beijing Railway Station was initially built for military use, but today, 1.5 million passengers ride the 2-yuan subway each day.

The existing subway network spans 155 km and has 93 stations. Three new lines will open shortly before the Games, to transport visitors to and from the new airport terminal and between the Bird's Nest and downtown, and construction of more lines will continue following them.

At least six others are already under construction, with an aim to stretch the network to more than 561 km and 420 stations.

20. Highest number of mascots - five

Multiple Olympic mascots are not uncommon, but for the first time more than three figures will share Summer Olympic mascot duty when the five Fuwa take center stage. 

Featuring four of China's most popular animals - the fish, the panda, the Tibetan antelope and the swallow - and the Olympic flame, the mascots' names are "Beibei," "Jingjing," "Huanhuan," "Yingying" and "Nini," which together reads in Chinese as "Beijing welcomes you".