Ni Dan, 20, and two of his classmates were sitting at the front of a long queue outside Gate No. 6 of the Shanghai Expo Park. They had been there for six hours and it was just 4 a.m. Sunday.

"We chose to visit Expo today for three reasons: it's Expo's 100th day, it's the two-year anniversary of the Beijing Olympic Games, plus it's the eighth day of the eighth month," Ni said. Eight is considered by many Chinese an auspicious number that brings fortune.

Just graduated from a high school in east China's Jiangsu Province, Ni and his friends will have to separate to study in colleges in different parts of China and some will even go abroad. "We want to mark our friendship with this special day," one of Ni's friends said.

Ni and his friends planned to stay in the park for 12 hours after they get in. "We may get tired. But it will be worth it."

The moon was still on the sky when more people were joining the long lines of thousands of people each, five hours before the gate would open.

Sitting on the ground or on 10-yuan (about 1.5 U.S. dollars) plastic foldable stools newly purchased from vendors, people chatted, played cards or meditated to reserve energy for a very long day of waiting, walking, viewing and waiting again.

"It would be a magnificent sight when the gate opens. Just imagine tens of thousands of people all wanting to get in at the same time," said He Wenping, 46, from central China's Hubei Province. On Saturday, she and her daughter came to the gate at 5 a.m. and managed to visit six pavilions. "We plan to finish all of them in three days."

Dashing at entrance

Coming early is a crucial link to get the limited reservation tickets for the China Pavilion and shorten the hours of waiting outside other pavilions. But a front position on the queue is not enough, "dashing as fast as you can is a must to secure a ticket", according to instructions posted online by experienced visitors.

When the gate opened at around 9 a.m., visitors holding those illustrated instructions, widely spread on the Internet, or bearing them in mind, began a 200-meter race to the safety checkpoints.

Already experienced the race once, He Wenping and her daughter brought as few things as possible and put them in their backpacks so that they wouldn't need to fumble their pockets at the safety check. "It saves about 10 seconds," said an instruction titled "1,000-Meter Race."

After getting the China Pavilion tickets from a machine at the end of the safety check, they had to continue running along a route marked out in red lines on the instruction to leave the crowds behind.

"By following the instructions, we can visit one or two popular pavilions before noon without lining for hours. Then we'll go to the China Pavilion with the reservation tickets in the afternoon," He said.

At first, Ni thought he need not hurry because he was on the first row. "I didn't feel like running after a night's wait. But people started to pass by us and some were pushing me from behind. Then, for a second, I felt worried, a night's wait cannot be in vain," he said.

After a moment of hesitation, Ni and his friends were on full gear. Young and athletic, they were among the first to pass the safety check and got the reservation tickets for the China Pavilion.

Tickets to the China Pavilion, given out free to visitors who came early, are used to curb waiting hours. With the ticketing system, it usually takes about an hour to enter the China Pavilion. While other popular pavilions often require three to five hours. At its peak, visitors had to wait for eight hours to get into the Saudi Arabia Pavilion.

As of 9:36 a.m., more than 127,000 visitors have entered the 5.28-square-km Expo Park.