1. Tickets: You don't need tickets to visit Peking University Tsinghua, but you need to register your identity.

2. Opening hours: open all year round, and open as usual on holidays. Normal work and rest time is enough.

Precautions:

1. You'd better buy a map, because the campus is big so as not to get lost.

2. Go to visit boldly, and students may dress up better.

3. Pay attention to keep the university environment quiet and elegant.

There will be many people in summer.