You can learn a lot of interesting information from taking a tour of a medical institution. Check to see if Kwong Wah Hospital is open to visitors while you're in the area.
Located in Mong Kok, this health care institution has free entry. It's the ideal place to go for an affordable and fun day out! If you're up for more exploring, Ocean Park, Lan Kwai Fong and Hong Kong - Macau Ferry Terminal are nearby.