April 23 marks World Book Day, organized by the United Nations Educational, Scientific and Cultural Organization (UNESCO). Meet Sun Shiquan, a 92-year-old reader in Chengkou County, southwest China's Chongqing Municipality, who has a collection of 7,000 books. He taught in his village's primary school after 1949, and the Chinese dictionary is the book he reads the most.

In Sun's eyes, there are two ways to understand the world: reading thousands of books and traveling thousands of miles. That's why more than 10 old-fashioned wooden cabinets are in his attic, displaying different kinds of books from different periods.