Do you know what audiovisual heritage is?  How is it relevant to the intangible cultural heritage?  And why should we preserve it?  The United Nations Educational, Scientific and Cultural Organization has designated 27 October as World Day for Audiovisual Heritage since 2005.  To echo this, film archives around the world organise various activities every year.  The Hong Kong Film Archive also designed a set of online teaching kit with professionals introducing audiovisual heritage in an interesting way.  Following the included lesson plan (Chinese only) and the interactive power point slides, teachers can lead students to explore the importance of audiovisual heritage and its historical and culture significance within a 60-minute lesson.