According to the Nanjing Municipal Bureau of Parks and Tourism, children under 1.3 meters (4 feet) tall are allowed free admission to the Yuyuan Lake scenic area in Gulou District, but they do need a ticket.
Children between 1.3 meters and 1.5 meters tall require a reduced-price ticket, which is usually around half the adult price.
However, please note that ticket policies may change or be subject to certain conditions (e.g., special events, peak seasons), so it’s always best to check with park staff or their official website for the most up-to-date information before your visit.