The expo site open to 00:00, the pavilions open to 22:30, you can buy a night ticket and visit the expo site at night, the night view is splendid!

We want to attend the evening as well. But given the reservation system, will there be reservation numbers left for the popular pavillions? i.e. would there be no reservations left for that day if we enter at 5pm for the china pavillion? thanks!

The reservation tickets are gone in ten to fifteen minutes in the morning after the gate opens. I've heard that some pavilions like the Taiwan pavilion may hand out one thousand reservation tickets at 6 PM at a designated place. Most pavilions that don't require reservations have a special entrance for those 70 and above and those in wheelchairs.